Rice Cultivar Designated &#39;CL272&#39;

ABSTRACT

The herbicide-tolerant rice cultivar designated ‘CL272’ and its hybrids and derivatives are disclosed. CL272 is a novel, herbicide-resistant, early maturing, semidwarf, medium-grain rice cultivar with improved yield and improved disease resistance. This invention also pertains to methods for producing a hybrid or new variety by crossing the rice variety ‘CL272’ with another rice line, one or more times. This invention allows for single-gene converted plants of ‘CL272.’ This invention also provides regenerable cells for use in tissue culture of rice plant ‘CL272.’ The present invention provides a method for treating rice.

The benefit of the 2 Jun. 2016 filing date of U.S. provisional patentapplication Ser. No. 62/344,657 is claimed under 35 U.S.C. § 119(e) inthe United States, and is claimed under applicable treaties andconventions in all countries.

TECHNICAL FIELD

This invention pertains to the rice cultivar designated ‘CL272,’ and tohybrids of, and cultivars derived from the rice cultivar designated‘CL272.’

BACKGROUND ART

Rice is an ancient agricultural crop, and remains one of the world'sprincipal food crops. There are two cultivated species of rice: Oryzasativa L., the Asian rice, and O. glaberrima Steud., the African rice.Oryza sativa L. constitutes virtually all of the world's cultivated riceand is the species grown in the United States. The three major riceproducing regions in the United States are the Mississippi Delta(Arkansas, Mississippi, northeast Louisiana, southeast Missouri), theGulf Coast (southwest Louisiana, southeast Texas); and the CentralValley of California. See generally U.S. Pat. No. 6,911,589.

Rice is a semiaquatic crop that benefits from flooded soil conditionsduring part or all of the growing season. In the United States, rice istypically grown on flooded soil to optimize grain yields. Heavy claysoils or silt loam soils with hard pan layers about 30 cm below thesurface are typical rice-producing soils, because they reduce water lossfrom soil percolation. Rice production in the United States can bebroadly categorized as either dry-seeded or water-seeded. In thedry-seeded system, rice is sown into a well-prepared seed bed with agrain drill or by broadcasting the seed and incorporating it with a diskor harrow. Moisture for seed germination comes from irrigation orrainfall. Another method of dry-seeding is to broadcast the seed byairplane into a flooded field, and then promptly drain the water fromthe field. For the dry-seeded system, when the plants have reachedsufficient size (four- to five-leaf stage), a shallow permanent flood ofwater 5 to 16 cm deep is applied to the field for the remainder of thecrop season. Some rice is grown in upland production systems, withoutflooding.

One method of water-seeding is to soak rice seed for 12 to 36 hours toinitiate germination, and then to broadcast the seed by airplane into aflooded field. The seedlings emerge through a shallow flood, or thewater may be drained from the field for a short time to enhance seedlingestablishment. A shallow flood is then maintained until the riceapproaches maturity. For both the dry-seeded and water-seeded productionsystems, the fields are drained when the crop is mature, and the rice isharvested 2 to 3 weeks later with large combines.

In rice breeding programs, breeders typically use the same productionsystems that predominate in the region. Thus, a drill-seeded breedingnursery is typically used by breeders in a region where rice isdrill-seeded, and a water-seeded nursery is typically used in regionswhere water-seeding prevails.

Rice in the United States is classified into three primary market typesby grain size, shape, and endosperm composition: long-grain,medium-grain, and short-grain. Typical U.S. long-grain cultivars cookdry and fluffy when steamed or boiled, while medium- and short-graincultivars cook moist and sticky. Medium grain rice is usually slightlywider than long grain rice and slightly shorter, with a length:widthratio between 2:1 and 3:1.

In the early 1980s about two thirds of Louisiana rice acreage wasplanted with medium grain cultivars. Market demand and the release ofsuperior long grain varieties (e.g., superior yield and superior diseaseresistance) caused medium-grain plantings to decline considerably overthe last 25 years or so. By the mid-1990s, Louisiana rice acreage wasplanted 65 percent long grains, and 35 percent medium grains. For thepast 10 years or so, less than 5 percent of Louisiana rice acreage hasbeen medium grains.

Long-grain cultivars have become the principal varieties grown, not justin Louisiana, but throughout the southern United States in recent years.However, there does remain demand for medium grain production in theregion, and recently that demand has increased substantially. Whilethere are several non-herbicide-resistant, medium-grain cultivarsavailable for the region, such as ‘Jupiter,’ Neptune,′ and ‘Bengal,’only one herbicide-resistant, medium grain rice cultivar has previouslybeen released, namely ‘CL261.’ See United States patent applicationpublication no. 2012/0204285.

There is an unfilled need for new herbicide-resistant, medium-grain ricecultivars, particularly those that are well-adapted for growingconditions in the southern United States. Medium grain rice is morecommon in California, but Southern U.S. medium grains differ somewhatfrom those grown in California. Additionally, the weed called “red rice”has been a substantial problem in medium grain rice fields in thesouthern United States.

Although specific breeding objectives vary somewhat in differentregions, increasing yield is a primary objective in all programs. Grainyield depends, in part, on the number of panicles per unit area, thenumber of fertile florets per panicle, and grain weight per floret.Increases in any or all of these components may help improve yields.Heritable variation exists for each of these components, and breedersmay directly or indirectly select for any of them.

There are numerous steps in the development of any novel, desirableplant germplasm. Plant breeding begins with the analysis and definitionof problems and weaknesses of the current germplasm, the establishmentof program goals, and the definition of specific breeding objectives.The next step is selection (or generation) of germplasm that possessesthe desired traits to meet the program goals. A goal is often to combinein a single variety an improved combination of desirable traits from twoor more ancestral germplasm lines. These traits may include such thingsas higher seed yield, resistance to disease or insects, better stems androots, tolerance to low temperatures, and better agronomiccharacteristics or grain quality.

The choice of breeding and selection methods depends on the mode ofplant reproduction, the heritability of the trait(s) being improved, andthe type of seed that is used commercially (e.g., F₁ hybrid, versus pureline or inbred cultivars). For highly heritable traits, a choice ofsuperior individual plants evaluated at a single location may sometimesbe effective, while for traits with low or more complex heritability,selection is often based on mean values obtained from replicatedevaluations of families of related plants. Selection methods includepedigree selection, modified pedigree selection, mass selection,recurrent selection, and combinations of these methods.

The complexity of inheritance influences the choice of breeding method.Backcross breeding is used to transfer one or a few favorable genes fora highly heritable trait into a desirable cultivar. This approach hasbeen used extensively for breeding disease-resistant cultivars. Variousrecurrent selection techniques are used to improvequantitatively-inherited traits controlled by numerous genes. The use ofrecurrent selection in self-pollinating crops depends on the ease ofpollination, the frequency of successful hybrids from each pollination,and the number of hybrid offspring from each successful cross.

Promising advanced breeding lines are thoroughly tested and compared toappropriate standards in environments representative of the commercialtarget area(s), typically for three or more years. The best lines becomecandidates for new commercial cultivars; those still deficient in a fewtraits may be used as parents to produce new populations for furtherselection.

These processes, which lead ultimately to marketing and distribution ofnew cultivars or hybrids, typically take 8 to 12 years from the time ofthe first cross; they may further rely on (and be delayed by) thedevelopment of improved breeding lines as precursors. Development of newcultivars and hybrids is a time-consuming process that requires preciseforward planning and efficient use of resources. There are neverassurances of a successful outcome.

A particularly difficult task is the identification of individual plantsthat are, indeed, genetically superior. A plant's phenotype results froma complex interaction of genetics and environment. One method foridentifying a genetically superior plant is to observe its performancerelative to other experimental plants and to a widely grown standardcultivar raised in an identical environment. Repeated observations frommultiple locations can help provide a better estimate of genetic worth.

The goal of rice breeding is to develop new, unique, and superior ricecultivars and hybrids. The breeder initially selects and crosses two ormore parental lines, followed by self-pollination and selection,producing many new genetic combinations. The breeder can generatebillions of different genetic combinations via crossing, selfing, andmutation breeding. The traditional breeder has no direct control ofgenetics at the molecular level. Therefore, two traditional breedersworking independently of one another will never develop the same line,or even very similar lines, with the same traits.

Each year, the plant breeder selects germplasm to advance to the nextgeneration. This germplasm is grown under different geographical,climatic, and soil conditions. Further selections are then made, duringand at the end of the growing season. The resulting cultivars (orhybrids) and their characteristics are inherently unpredictable. This isbecause the traditional breeder's selection occurs in uniqueenvironments, with no control at the molecular level, and withpotentially billions of different possible genetic combinations beinggenerated. A breeder cannot predict the final resulting line, exceptpossibly in a very gross and generic fashion. Further, the same breedermay not produce the same cultivar twice, even starting with the sameparental lines, using the same selection techniques. This uncontrollablevariation results in substantial effort and expenditures in developingsuperior new rice cultivars (or hybrids); and makes each new cultivar(or hybrid) novel and unpredictable.

The selection of superior hybrid crosses is conducted slightlydifferently. Hybrid seed is typically produced by manual crosses betweenselected male-fertile parents or by using genetic male sterilitysystems. These hybrids are typically selected for single gene traitsthat unambiguously indicate that a plant is indeed an F₁ hybrid that hasinherited traits from both presumptive parents, particularly the maleparent (since rice normally self-fertilizes). Such traits might include,for example, a semi dwarf plant type, pubescence, awns, or apiculuscolor. Additional data on parental lines, as well as the phenotype ofthe hybrid, influence the breeder's decision whether to continue with aparticular hybrid cross or an analogous cross, using related parentallines.

Pedigree breeding and recurrent selection breeding methods are sometimesused to develop cultivars from breeding populations. These breedingmethods combine desirable traits from two or more cultivars or othergermplasm sources into breeding pools from which cultivars are developedby selfing and selection of desired phenotypes. The new cultivars areevaluated to determine commercial potential.

Pedigree breeding is often used to improve self-pollinating crops. Twoparents possessing favorable, complementary traits are crossed toproduce F₁ plants. An F₂ population is produced by selfing one or moreF₁s. Selection of the superior individual plants may begin in the F₂ (orlater) generation. Then, beginning in the F₃ (or other subsequent)generation, individual plants are selected. Replicated testing ofpanicle rows from the selected plants can begin in the F₄ (or othersubsequent) generation, both to fix the desired traits and to improvethe effectiveness of selection for traits that have low heritability. Atan advanced stage of inbreeding (e.g., F₆ or F₇), the best lines ormixtures of phenotypically-similar lines are tested for potentialrelease as new cultivars.

Mass and recurrent selection methods can also be used to improvepopulations of either self- or cross-pollinating crops. A geneticallyvariable population of heterozygous individuals is either identified orcreated by intercrossing several different parents. The best offspringplants are selected based on individual superiority, outstandingprogeny, or excellent combining ability. The selected plants areintercrossed to produce a new population in which further cycles ofselection are continued.

Backcross breeding is often used to transfer genes for a simplyinherited, highly heritable trait into a desirable homozygous cultivaror inbred line, which is the recurrent parent. The source of the traitto be transferred is called the donor parent. The resulting plant shouldideally have the attributes of the recurrent parent (e.g., cultivar) andthe desired new trait transferred from the donor parent. After theinitial cross, individuals possessing the desired donor phenotype (e.g.,disease resistance, insect resistance, herbicide tolerance) are selectedand repeatedly crossed (backcrossed) to the recurrent parent.

The single-seed descent procedure in the strict sense refers to plantinga segregating population, harvesting a sample of one seed per plant, andusing the one-seed sample to plant the next generation. When thepopulation has been advanced from the F₂ generation to the desired levelof inbreeding, the several plants from which the lines are derived willeach trace to different F₂ individuals. The number of plants in apopulation declines each generation due to failure of some seeds togerminate or the failure of some plants to produce at least one seed. Asa result, not all of the F₂ plants originally sampled in the populationwill be represented by progeny in subsequent generations.

In a multiple-seed procedure, the breeder harvests one or more seedsfrom each plant in a population and threshes them together to form abulk. Part of the bulk is used to plant the next generation and part isheld in reserve. The procedure has been referred to as modifiedsingle-seed descent or the pod-bulk technique. The multiple-seedprocedure has been used to save labor at harvest. It is considerablyfaster to thresh panicles by machine than to remove one seed from eachby hand as in the single-seed procedure. The multiple-seed procedurealso makes it possible to plant the same number of seeds from apopulation for each generation of inbreeding. Enough seeds are harvestedto compensate for plants that did not germinate or produce seed.

Other common and less-common breeding methods are known and used in theart. See, e.g., R. W. Allard, Principles of Plant Breeding (John Wileyand Sons, Inc., New York, N.Y., 1967); N. W. Simmonds, Principles ofCrop Improvement (Longman, London, 1979); J. Sneep et al., PlantBreeding Perspectives (Pudoc, Wageningen, 1979); and W. R. Fehr,Principles of Cultivar Development: Theory and Technique (MacmillanPub., New York, N.Y., 1987).

Proper testing should detect any major faults and establish the level ofsuperiority or improvement over current cultivars. In addition toshowing superior performance, there must be a demand for a new cultivaror hybrid; i.e., the new cultivar or hybrid should either be compatiblewith industry standards, or it should create a new market. Theintroduction of a new cultivar or hybrid may incur additional costs tothe seed producer, the grower, processor, and consumer for such thingsas special advertising and marketing, altered seed and commercialproduction practices, and new product utilization. The testing thatprecedes the release of a new cultivar or hybrid should take intoaccount research and development costs, in addition to technicalsuperiority of the final cultivar or hybrid.

In recent years, a few herbicide-tolerant rice varieties and hybridshave been successfully introduced to the market. See, e.g., U.S. Pat.Nos. 5,545,822; 5,736,629; 5,773,703; 5,773,704; 5,952,553; 6,274,796;6,943,280; 7,019,196; 7,345,221; 7,399,905; 7,495,153; 7,754,947;7,786,360; 8,598,080; 8,841,525; 8,841,526; 8,946,528; 9,029,642;9,090,904; and 9,220,220. These herbicide-tolerant rice plants areresistant to or tolerant of herbicides that normally inhibit the growthof rice plants. Thus, rice growers now can control weeds that previouslywere difficult to control in rice fields, including “red rice.” “Redrice” is a weedy relative of cultivated rice, and had previously beendifficult to control because it actually belongs to the same genus(Oryza), and sometimes even the same species (O. sativa) as cultivatedrice. Only recently, when herbicide tolerant rice became available, didit become possible to control red rice with herbicides in fields wherecultivated rice was growing contemporaneously. There are currently onlya limited number of herbicide-tolerant rice cultivars and hybridsavailable commercially. There is a continuing need for newherbicide-tolerant cultivars and hybrids—that is, rice plants that notonly express a desired herbicide-tolerant phenotype, but that alsopossess other agronomically desirable characteristics. Additionalherbicide-tolerant cultivars and hybrids will provide rice growersgreater flexibility in planting and managing crops.

DISCLOSURE OF THE INVENTION

I have discovered a novel, herbicide-resistant, early maturing,semidwarf, medium-grain rice cultivar with improved yield and improveddisease resistance, designated ‘CL272.’

This invention also pertains to methods for producing a hybrid or newvariety by crossing the rice variety ‘CL272’ with another rice line, oneor more times. Thus any such methods using the rice variety ‘CL272’ areaspects of this invention, including backcrossing, hybrid production,crosses to populations, and other breeding methods involving ‘CL272.’Hybrid plants produced using the rice variety ‘CL272’ as a parent arealso within the scope of this invention. Optionally, either parent can,through routine manipulation of cytoplasmic or other factors throughtechniques known in the art, be produced in a male-sterile form.

In another embodiment, this invention allows for single-gene convertedplants of ‘CL272.’ The single transferred gene may be a dominant orrecessive allele. Preferably, the single transferred gene confers atrait such as resistance to insects; resistance to one or morebacterial, fungal or viral diseases; male fertility or sterility;enhanced nutritional quality; enhanced processing qualities; or anadditional source of herbicide resistance. The single gene may be anaturally occurring rice gene or a transgene introduced through geneticengineering techniques known in the art. The single gene also may beintroduced through traditional backcrossing techniques or genetictransformation techniques known in the art.

In another embodiment, this invention provides regenerable cells for usein tissue culture of rice plant ‘CL272.’ The tissue culture may allowfor regeneration of plants having physiological and morphologicalcharacteristics of rice plant ‘CL272’ and of regenerating plants havingsubstantially the same genotype as rice plant ‘CL272.’ Tissue culturetechniques for rice are known in the art. The regenerable cells intissue culture may be derived from sources such as embryos, protoplasts,meristematic cells, callus, pollen, leaves, anthers, root tips, flowers,seeds, panicles, or stems. In addition, the invention provides riceplants regenerated from such tissue cultures.

In another embodiment, the present invention provides a method forcontrolling weeds in the vicinity of rice. The method comprisescontacting the rice with a herbicide, wherein said rice belongs to anyof (a) variety ‘CL272’ or (b) a hybrid, derivative, or progeny of‘CL272’ that expresses the imidazolinone herbicide resistancecharacteristics of ‘CL272.’

In some embodiments, the herbicide is an imidazolinone herbicide, asulfonylurea herbicide, or a combination thereof.

In one embodiment, the rice is a rice plant and said contactingcomprises applying the herbicide in the vicinity of the rice plant.

In another embodiment, the herbicide is applied to weeds in the vicinityof the rice plant.

In still further embodiments, the rice is a rice seed and saidcontacting comprises applying the herbicide to the rice seed.

In some embodiments, the present invention provides a method fortreating rice. The method comprises contacting the rice with anagronomically acceptable composition, wherein said rice belongs to anyof (a) variety ‘CL272’ or (b) a hybrid, derivative, or progeny of‘CL272’ that expresses the imidazolinone herbicide resistancecharacteristics of ‘CL272.’

In one embodiment, the agronomically acceptable composition comprises atleast one agronomically acceptable active ingredient.

In another embodiment, the agronomically acceptable active ingredient isselected from the group consisting of fungicides, insecticides,antibiotics, stress tolerance-enhancing compounds, growth promoters,herbicides, molluscicides, rodenticides, and animal repellants, andcombinations thereof.

In some embodiments, the rice plants of the present invention includeplants that comprise an AHASL polypeptide (acetohydroxyacid synthaselarge subunit) having, relative to the wild-type AHASL polypeptide, anasparagine (N) at amino acid position 653 (Arabidopsis thaliana AHASLnumbering) or equivalent position, wherein such a plant has increasedtolerance to an imidazolinone herbicide when compared to a wild-typerice plant.

Amino acid position 653 of Arabidopsis thaliana AHASL corresponds toamino acid position 627 of Oryza sativa AHASL. In the wild-type riceAHASL polypeptide, this position is a serine.

In other embodiments, the rice plants of the present invention includeplants that comprise an AHASL polypeptide having a full-length, matureAHASL sequence variant, wherein there is an asparagine at amino acidposition 653 (Arabidopsis thaliana AHASL numbering) or equivalentposition and (ii) one or more conservative substitutions at one or morenon-essential amino acid residues.

In one embodiment, the full-length, mature AHASL sequence variant has,over the full-length of the variant, at least about 95%, illustratively,at least about: 95%, 96%, 97%, 98%, 99%, 99.5%, and 99.9% sequenceidentity to the wild type, aside from the serine-asparagine substitutiondescribed above.

In some embodiments, the present invention provides a progeny rice lineor variety obtainable from rice line ‘CL272,’ a representative sample ofseeds of said line ‘CL272’ having been deposited under ATCC AccessionNo. PTA-123124, said line ‘CL272’ having been produced by a processcomprising:

(a) providing a rice seed of the Cypress variety (USDA ARS GRIN NPGSAccession No. PI 561734); and(b) mutagenizing said rice seed to produce an altered plant thatcontains in its genome an AHASL gene encoding an AHASL polypeptidehaving, relative to the wild-type AHASL polypeptide of the Cypress rice,an asparagine (N) substitution at amino acid position 653 (Arabidopsisthaliana AHASL numbering) or equivalent position, and further breedingthe altered plant, wherein said altered plant of step (b) exhibits, uponexpression of said AHASL gene, an increased tolerance to animidazolinone herbicide as compared to that of plants of said Cypressvariety, and plants of said line ‘CL272’ and plants of said progeny lineor variety contain said AHASL gene and exhibit said increased tolerance.

In other embodiments, the present invention provides a progeny rice lineor variety obtained from rice line ‘CL272,’ a representative sample ofseeds of said line ‘CL272’ having been deposited under ATCC AccessionNo. PTA-123124, said line ‘CL272’ having been produced by a processcomprising:

(a) providing a rice seed of the Cypress variety (USDA ARS GRIN NPGSAccession No. PI 561734); and(b) mutagenizing said rice seed to produce an altered plant thatcontains in its genome an AHASL gene encoding an AHASL polypeptidehaving, relative to the wild-type AHASL polypeptide of the Cypress rice,an asparagine (N) substitution at amino acid position 653 (Arabidopsisthaliana AHASL numbering) or equivalent position, and further breedingthe altered plant, wherein said altered plant of step (b) exhibits, uponexpression of said AHASL gene, an increased tolerance to animidazolinone herbicide as compared to that of plants of said Cypressvariety, and plants of said line ‘CL272’ and plants of said progeny lineor variety contain said AHASL gene and exhibit said increased tolerance.

In some embodiments, the present invention provides a progeny rice plantobtainable from rice line ‘CL272,’ a representative sample of seeds ofsaid line ‘CL272’ having been deposited under ATCC Accession No.PTA-123124, said line ‘CL272’ having been produced by a processcomprising:

(a) providing a rice seed of the Cypress variety (USDA ARS GRIN NPGSAccession No. PI 561734); and(b) mutagenizing said rice seed to produce an altered plant thatcontains in its genome an AHASL gene encoding an AHASL polypeptidehaving, relative to the wild-type AHASL polypeptide of the Cypress rice,an asparagine (N) substitution at amino acid position 653 (Arabidopsisthaliana AHASL numbering) or equivalent position, and further breedingthe altered plant, wherein said altered plant of step (b) exhibits, uponexpression of said AHASL gene, an increased tolerance to animidazolinone herbicide as compared to that of plants of said Cypressvariety, and plants of said line ‘CL272’ and said progeny rice plantcomprise said AHASL gene and exhibit said increased tolerance.

In some embodiments, the present invention provides a progeny rice plantobtained from rice line ‘CL272,’ a representative sample of seeds ofsaid line ‘CL272’ having been deposited under ATCC Accession No.PTA-123124, said line ‘CL272’ having been produced by a processcomprising:

(a) providing a rice seed of the Cypress variety (USDA ARS GRIN NPGSAccession No. PI 561734); and(b) mutagenizing said rice seed to produce an altered plant thatcontains in its genome an AHASL gene encoding an AHASL polypeptidehaving, relative to the wild-type AHASL polypeptide of the Cypress rice,an asparagine (N) substitution at amino acid position 653 (Arabidopsisthaliana AHASL numbering) or equivalent position, and further breedingthe altered plant, wherein said altered plant of step (b) exhibits, uponexpression of said AHASL gene, an increased tolerance to animidazolinone herbicide as compared to that of plants of said Cypressvariety, and plants of said line ‘CL272’ and said progeny rice plantcomprise said AHASL gene and exhibit said increased tolerance.

In another embodiment, the present invention provides a progeny riceplant of rice line ‘CL272,’ a representative sample of seeds of saidline ‘CL272’ having been deposited under ATCC Accession No. PTA-123124,the progeny rice plant being obtainable by a process comprising:

(a) providing a plant of line ‘CL272,’ or tissue, seed, or cell thereof;and(b) mutagenizing or transforming said plant, tissue, seed, or cell ofstep (a) to produce an altered plant that contains in its genome anAHASL gene encoding an AHASL polypeptide having, relative to thewild-type AHASL polypeptide of a wild-type rice plant, an asparagine (N)substitution at amino acid position 653 (Arabidopsis thaliana AHASLnumbering) or equivalent position, and optionally further breeding thealtered plant, wherein said altered plant of step (b) exhibits, uponexpression of said AHASL gene, an increased tolerance to animidazolinone herbicide as compared to that of the wild-type rice plant.

In another embodiment, the present invention provides a progeny riceplant of rice line ‘CL272,’ a representative sample of seeds of saidline ‘CL272’ having been deposited under ATCC Accession No. PTA-123124,the progeny rice plant being obtained by a process comprising:

(a) providing a plant of line ‘CL272,’ or tissue, seed, or cell thereof;and(b) mutagenizing or transforming said plant, tissue, seed, or cell ofstep (a) to produce an altered plant that contains in its genome anAHASL gene encoding an AHASL polypeptide having, relative to thewild-type AHASL polypeptide of a wild-type rice plant, an asparagine (N)substitution at amino acid position 653 (Arabidopsis thaliana AHASLnumbering) or equivalent position, and optionally further breeding thealtered plant, wherein said altered plant of step (b) exhibits, uponexpression of said AHASL gene, an increased tolerance to animidazolinone herbicide as compared to that of the wild-type rice plant.

In other embodiments, the present invention provides a method forcontrolling weeds in a field, said method comprising:

-   -   growing, in a field, a plant according to the present invention;        and    -   contacting said plant and weeds in the field with an effective        amount of an AHAS-inhibiting herbicide to which the plant is        tolerant, thereby controlling the weeds.

In some embodiments, improved rice plants and rice lines havingtolerance to at least one AHAS-inhibitor herbicide are provided. In someembodiments, the AHAS-inhibitor herbicide is an imidazolinone herbicide.In some embodiments, the imidazolinone herbicide is imazethapyr,imazaquin, imazapyr, imazamox, or combinations thereof. Several examplesof commercially available imidazolinone herbicides are, withoutlimitation, PURSUIT® (imazethapyr), SCEPTER® (imazaquin), ARSENAL®(imazapyr), and Raptor™ Herbicide (imazamox). In some embodiments, theAHAS-inhibitor herbicide is a sulfonylurea herbicide. In one embodiment,the sulfonylurea herbicide is nicosulfuron.

The rice plants and rice lines of the present invention also provide forimproved systems and methods for controlling weeds using at least oneAHAS-inhibitor herbicide. In some embodiments, the AHAS-inhibitorherbicide is an imidazolinone herbicide. In some embodiments, theimidazolinone herbicide is imazethapyr, imazaquin, imazapyr, imazamox,or combinations thereof. In some embodiments, the AHAS-inhibitorherbicide is a sulfonylurea herbicide. In one embodiment, thesulfonylurea herbicide is nicosulfuron.

In some embodiments, the AHAS-inhibitor herbicide is an imidazolinoneherbicide, a sulfonylurea herbicide, or combinations thereof.

Definitions

The following definitions apply throughout the specification and claims,unless context clearly indicates otherwise:

“Days to 50% heading.” Average number of days from seeding to the daywhen 50% of all panicles are exerted at least partially through the leafsheath. A measure of maturity.

“Grain Yield.” Grain yield is measured in pounds per acre, at 12.0%moisture. Grain yield depends on a number of factors, including thenumber of panicles per unit area, the number of fertile florets perpanicle, and grain weight per floret.

“Lodging Percent.” Lodging is a subjectively measured rating, and is thepercentage of plant stems leaning or fallen completely to the groundbefore harvest.

“Grain Length (L).” Length of a rice grain, or average length, measuredin millimeters.

“Grain Width (W).” Width of a rice grain, or average width, measured inmillimeters.

“Length/Width (L/W) Ratio.” This ratio is determined by dividing theaverage length (L) by the average width (W).

“1000 Grain Wt.” The weight of 1000 rice grains, measured in grams.

“Harvest Moisture.” The percentage moisture in the grain when harvested.

“Plant Height.” Plant height in centimeters, measured from soil surfaceto the tip of the extended panicle at harvest.

“Apparent Amylose Percent.” The percentage of the endosperm starch ofmilled rice that is amylose. The apparent amylose percent is animportant grain characteristic that affects cooking behavior. Standardlong grains contain 20 to 23 percent amylose. Rexmont-type long grainscontain 24 to 25 percent amylose. Short and medium grains contain 13 to19 percent amylose. Waxy rice contains zero percent amylose. Amylosevalues, like most characteristics of rice, depend on the environment.“Apparent” refers to the procedure for determining amylose, which mayalso involve measuring some long chain amylopectin molecules that bindto some of the amylose molecules. These amylopectin molecules actuallyact similar to amylose in determining the relative hard or soft cookingcharacteristics.

“Alkali Spreading Value.” An index that measures the extent ofdisintegration of the milled rice kernel when in contact with dilutealkali solution. It is an indicator of gelatinization temperature.Standard long grains have a 3 to 5 Alkali Spreading Value (intermediategelatinization temperature).

“Peak Viscosity.” The maximum viscosity attained during heating when astandardized, instrument-specific protocol is applied to a defined riceflour-water slurry.

“Trough Viscosity.” The minimum viscosity after the peak, normallyoccurring when the sample starts to cool.

“Final Viscosity.” Viscosity at the end of the test or cold paste.

“Breakdown.” The peak viscosity minus the hot paste viscosity.

“Setback.” Setback 1 is the final viscosity minus the trough viscosity.Setback 2 is the final viscosity minus the peak viscosity.

“RVA Viscosity.” Viscosity, as measured by a Rapid Visco Analyzer, awidely used laboratory instrument to examine the paste viscosity orthickening ability of milled rice during the cooking process.

“Hot Paste Viscosity.” Viscosity measure of rice flour/water slurryafter being heated to 95° C. Lower values indicate softer and stickiercooking types of rice.

“Cool Paste Viscosity.” Viscosity measure of rice flour/water slurryafter being heated to 95° C. and uniformly cooled to 50° C. Values lessthan 200 indicate softer cooking types of rice.

“Allele.” An allele is any of one or more alternate forms of the samegene. In a diploid cell or organism such as rice, the two alleles of agiven gene occupy corresponding loci on a pair of homologouschromosomes.

“Backcrossing.” Backcrossing is a process in which a breeder repeatedlycrosses hybrid progeny back to one of the parents, for example, crossinga first generation hybrid F₁ with one of the parental genotypes of theF₁ hybrid, and then crossing a second generation hybrid F₂ with the sameparental genotype, and so forth.

“Essentially all the physiological and morphological characteristics.” Aplant having “essentially all the physiological and morphologicalcharacteristics” of a specified plant refers to a plant having the samegeneral physiological and morphological characteristics, except forthose characteristics that are derived from a particular converted gene.

“Quantitative Trait Loci (QTL).” Quantitative trait loci (QTL) refer togenetic loci that to some degree control numerically measurable traits,generally traits that are continuously distributed.

“Regeneration.” Regeneration refers to the development of a plant fromtissue culture.

“Single Gene Converted (Conversion).” Single gene converted (conversion)includes plants developed by backcrossing wherein essentially all of thedesired morphological and physiological characteristics of a parentalvariety are recovered, while also retaining a single gene that istransferred into the plants via crossing and backcrossing. The term canalso refer to the introduction of a single gene through geneticengineering techniques known in the art.

MODES FOR CARRYING OUT THE INVENTION

‘CL272’ is a semidwarf, early-maturing, medium-grain rice line withexcellent grain yield and good grain quality. The new variety hastypical medium-grain cooking quality, grain dimensions, and cerealchemistry characteristics. ‘CL272’ was selected from the crossNeptune//Bengal/CL161. ‘CL272’ contains, by direct descent, the sameallele for herbicide resistance as that found in the cultivar ‘CL161.’‘Neptune’ and ‘Bengal’ are both publicly-released rice varieties, while‘CL161’ is a proprietary variety that is widely available commercially.‘CL161’ is an imazethapyr-resistant mutant derived from the variety‘Cypress.’ See U.S. Pat. No. 7,019,196. ‘CL272’ is highly resistant toimidazolinone herbicides, including but not limited to imazethapyr andimazamox. The herbicide resistance characteristics of ‘CL272’ areessentially identical to the herbicide resistance characteristics of thevariety ‘CL161’ (ATCC deposit PTA-904), also known as line PWC16 asdisclosed by U.S. Pat. Nos. 6,943,280 and 7,019,196, each of which isincorporated herein by reference in its entirety. Further, U.S. Pat. No.6,943,280 discloses that in the AHAS enzyme DNA sequence of line PWC16,the codon corresponding to amino acid 627 is AAT, which encodesasparagine, versus AGT (serine) for the wild-type, and that thisserine-to-asparagine substitution is believed to be responsible for theherbicide resistance displayed by the AHAS enzyme of line PWC16. ‘CL272’and its hybrids and derived varieties are adapted for growing throughoutthe rice growing areas of Louisiana, Texas, Arkansas, Mississippi andMissouri; and will also be well-suited for growing in many otherrice-producing areas throughout the world.

The development history of ‘CL272,’ also known as LA1402008, was asfollows:

Pedigree=NEPTUNE//BNGL/CL161

TABLE A Year Generation Entry No. 2009 F0 09CR 051 2010 F1 10T 051 2010F2 10B 2035 2011 F3 11-38915 2012 F4 CLPY 341 (panicle row increase)2013 F5 CA 253, CLR 014 (panicle row increase) 2014 F6 URN 008, CA 230,CLR 010 (panicle row increase)  2014/ F7 URN 008, CA 230, CLR 010 2015(panicle row increase) 2015 F8 URN 022, CA 211, CLR 003, CLPR 207, CLPS212, DP 005 (production of breeder/foundation seed)

‘CL272’ or LA1402008 is a semidwarf, early-maturing, medium-grainClearfield rice line with excellent grain yield and good grain quality.It was developed by pedigree selection at the LSU AgCenter's RiceResearch Station (RRS) in Crowley, La. ‘CL272’ was selected from thecross Neptune//Bengal/CL161, originally made at the LSU Rice ResearchStation in 2009. The line was developed from the bulk of a single F3line (11-38915) made at the Rice Research Station in 2011. ‘Neptune’ isan early-maturing, medium-grain variety publicly released by the LSURice Research Station in 2008. ‘Bengal’ is an early-maturing,medium-grain rice variety publicly released by the LSU Rice ResearchStation in 1992. ‘CL161’ is a proprietary variety that is widelyavailable commercially. LA1402008 was evaluated in a Preliminary YieldTrial at the LSU Rice Research Station in 2012 with the experimentaldesignation CLPY 341 before being entered into the Cooperative UniformRegional Rice Nurseries (URN) in 2014 with the designation RU1402008.

‘CL272’ averaged 38 inches in height in yield tests, one inch tallerthan the varieties ‘CL271’ and ‘Jupiter.’ ‘CL272’, ‘CL271,’ and‘Jupiter’ all averaged 85 days to 50% heading in testing over multipleyears and at multiple locations.

The leaves, lemma, and palea of ‘CL272’ are glabrous. The spikelet andapiculus are straw-colored. The grain is non-aromatic.

‘CL272’ has a typical medium-grain cooking quality with low amylosecontent and low gelatinization temperature. The average amylose contentof ‘CL272’ is 16.4%, compared with 15.0% and 14.7% for ‘CL271’ and‘Jupiter,’ respectively. The average alkali spread value of ‘CL272’ is6.2, compared with 6.2 and 6.0 for ‘CL271’ and ‘Jupiter,’ respectively.

‘CL272’ is moderately resistant to Cercospora, and is moderatelysusceptible to bacterial panicle blight, sheath blight, blast, andstraighthead.

Variants observed and removed from ‘CL272’ increase fields included anyshowing one or more of the following traits: pubescent, taller, shorter,later, earlier, short-, long- and intermediate-grain types, gold andblack hull, and sterile panicle. The total number of variants was lessthan 1 per 5000 plants.

Variety Description Information

Rice cultivar ‘CL272’ was observed to possess the followingmorphological and other characteristics, based on averages of testsconducted at multiple over several growing seasons; data for othervarieties are shown for comparison:

TABLE B Summary of Data Performance Number Refer- Trait CL272 CL261CL271 Jupiter of Tests ence Yield 8654 7452 8232 8119 18 Table 3 Whole53.9 62.5 58.5 61.5 7 Table 7 Total 71.1 71.1 71.7 68.4 7 Table 11Length-Rough 8.13 8.08 8.38 8.32 Table 33 Width-Rough 3.10 2.93 3.133.15 L/W Ratio- 2.62 2.76 2.68 2.64 Rough Thickness- 2.11 1.99 2.33 2.20Rough Weight-Rough 23.30 24.62 26.67 25.32 Length-Brown 6.09 6.05 6.266.07 Width-Brown 2.67 2.59 2.68 2.66 L/W Ratio- 2.28 2.34 2.34 2.28Brown Thickness- 1.87 1.77 1.92 1.97 Brown Weight-Brown 19.87 20.1322.20 22.67 Length-Milled 5.63 5.75 6.06 5.75 Width-Milled 2.52 2.512.65 2.64 L/W Ratio- 2.23 2.29 2.29 2.18 Milled Thickness- 1.83 1.701.87 1.89 Milled Weight-Milled 17.02 16.91 20.00 20.30 Vigor 4 4 4 5 12Table 15 Height 38 38 37 37 17 Table 19 Days to 50% 87 84 87 88 17 Table23 Sheath Blight 4.9 5.3 4.0 3.4 3 Table 25 Blast 2.9 4.5 2.0 2.5 3Table 26 Cercospora 0.7 0.7 1.0 1.0 1 Table 27 Bacterial 3.9 4.0 3.8 2.32 Table 28 Panicle Blight Straighthead 5.6 5.3 4.9 5.3 2 Table 29

TABLE 1 Main crop yield (lb/A) for CL272 (2012) YEAR TEST CL272 2012CLPY-RRS 8048 Note: 1 lb/A = 1 pound/acre = 1.12 kilogram/hectare

TABLE 2 Average main crop yields (lb/A) for CL272, CL261 and CL271across several trials at multiple locations in Louisiana (2013-2014).YEAR TEST CL272 CL261 CL271 2013 CL MULTI-RRS 9549 8683 9229 CL MULTI-EVANGELINE 10212  8929 10028  CL MULTI-LAKE ARTHUR 8854 8467 8491 CLMULTI-RICHLAND 9159 8674 9139 2013 Average 9443 8688 9222 2014 CLMULTI-RRS 9953 8924 9970 CL MULTI-EVANGELINE 9309 8275 9400 CL MULTI *LAKE ARTHUR 7976 8333 8886 2014 Average 9079 8511 9352 2013-2014 GrandAverage 9287 8612 9278

TABLE 3 Average main crop yields (lb/A) for CL272, CL261, CL271 andJupiter across several trials at multiple locations in Louisiana(2013-2015). YEAR TEST CL272 CL261 CL271 JUPITER 2013 CA-RRS 9322 82478481 9440 CA-ACADIA 9042 8577 8893 8178 CA-EVANGELINE 8763 7761 84167360 CA-JEFF DAVIS 6936 6924 6483 5879 CA-ST. LANDRY 7350 5704 6633 7420CA FRANKLIN 12277 9739 11242 10524 2013 Average 8948 7825 8358 8133 2014CA-RRS 10841 8831 10118 11452 CA-ACADIA 9223 8164 8356 10170CA-EVANGELINE 10154 7705 8481 8768 CA-JEFF DAVIS 7797 6591 6831 5370CA-LAKE ARTHUR 9200 8923 8773 7911 CA-ST LANDRY 7617 8785 8181 9070 2014Average 9139 8167 8457 8790 2015 CA-RRS 8704 7253 8804 9302 CA-ACADIA7154 4167 7313 7508 CA-EVANGELINE 5970 6427 5938 6050 CA-JEFF DAVIS 80574765 8378 7650 CA-LAKE ARTHUR 8548 6843 8327 8159 CA-ST LANDRY 8811 87318528 5929 2015 Average 7874 6365 7881 7433 2013-2015 8654 7452 8232 8119Grand Average

TABLE 4 Average main crop yields (lb/A) for CL272, CL271 and Jupiteracross several trials at multiple locations (2014-2015). YEAR TEST CL272CL271 JUPITER 2014 URN-LOUISIANA 11010 10900 10795 URN-ARKANSAS 914010369 12777 URN-MISSISSIPPI 10612 10296 9652 URN-MISSOURI 10821 1100111258 2014 Average 10396 10642 11121 2015 URN-LOUISIANA 9351 9529 9547URN-ARKANSAS 8775 7930 9949 URN-MISSISSIPPI 8514 8820 8699 DATE OFPLANTING 3-RRS 6555 6322 6971 DATE OF PLANTING 5-RRS 4521 5100 5045 2015Average 7543 7540 8042 2014-2015 Grand Average 8811 8919 9410

TABLE 5 Whole rice yield (%) for CL272 (2012) YEAR TEST CL272 2012CLPY-RRS 60.3

TABLE 6 Whole rice yield (%) for CL272, CL261 and CL271 across severaltrials at multiple locations in Louisiana (2013-2014). YEAR TEST CL272CL261 CL271 2013 CL MULTI-RRS 61.1 63.4 62.1 2014 CL MULTI-RRS 72.5 72.672.5 CL MULTI-LAKE ARTHUR 67.6 71.1 70.3 2014 Average 70.1 71.9 71.42013-2014 Grand Average 67.1 69.0 68.3

TABLE 7 Whole rice yield (%) for CL272, CL261, CL271 and Jupiter acrossseveral trials at multiple locations in Louisiana (2013-2015). YEAR TESTCL272 CL261 CL271 JUPITER 2013 CA-RRS 62.1 64.2 60.7 56.4 CA-ACADIA 55.161.6 60.9 59.3 2013 Average 58.6 62.9 60.8 57.8 2014 CA-RRS 66.9 66.368.6 63.4 CA-LAKE ARTHUR 66.2 67.5 69.1 63.4 2014 Average 66.6 66.9 68.963.4 2015 CA-RRS 52.3 68.4 59.4 68.2 CA-ACADIA 32.4 39.0 38.3 64.8CA-JEFF DAVIS 42.0 70.6 52.3 54.8 2015 Average 42.2 59.3 50.0 62.62013-2015 Grand Average 53.9 62.5 58.5 61.5

TABLE 8 Whole rice yield (%) for CL272, CL271 and Jupiter across severaltrials at multiple locations (2014-2015). YEAR TEST CL272 CL271 JUPITER2014 URN-LOUISIANA 66.2 66.5 64.1 URN-ARKANSAS 70.9 61.8 70.4URN-MISSISSIPPI 52.9 56.8 58.4 URN-TEXAS 61.7 62.3 67.7 URN-MISSOURI68.3 67.8 67.0 2014 Average 64.6 63.2 65.0 2015 URN-LOUISIANA 62.4 70.768.3 2014-2015 Grand Average 64.1 64.7 65.6

TABLE 9 Total rice yield (%) for CL272 (2012) YEAR TEST CL272 2012CLPY-RRS 67.0

TABLE 10 Total rice yield (%) for CL272, CL261 and CL271 across severaltrials at multiple locations in Louisiana (2013-2014). YEAR TEST CL272CL261 CL271 2013 CL MULTI-RRS 68.4 68.6 69.3 2014 CL MULTI-RRS 75.1 75.174.7 CL MULTI-LAKE ARTHUR 75.0 74.6 75.3 2014 Average 75.1 74.8 75.02013-2014 Grand Average 72.8 72.8 73.1

TABLE 11 Total rice yield (%) for CL272, CL261, CL271 and Jupiter acrossseveral trials at multiple locations in Louisiana (2013-2015). YEAR TESTCL272 CL261 CL271 JUPITER 2013 CA-RRS 68.2 68.6 69.8 63.2 CA-ACADIA 69.369.2 70.1 66.5 2013 Average 68.7 68.9 70.0 64.9 2014 CA-RRS 70.2 71.372.1 68.1 CA-LAKE ARTHUR 71.1 72.2 72.8 68.1 2014 Average 70.7 71.8 72.468.1 2015 CA-RRS 72.6 69.9 70.5 70.5 CA-ACADIA 74.1 72.3 73.6 72.3CA-JEFF DAVIS 71.9 73.9 72.9 69.8 2015 Average 72.9 72.0 72.3 70.92013-2015 Grand Average 71.1 71.1 71.7 68.4

TABLE 12 Total rice yield (%) for CL272, CL271 and Jupiter acrossseveral trials at multiple locations (2014-2015). YEAR TEST CL272 CL271JUPITER 2014 URN-LOUISIANA 68.6 73.2 68.7 URN-ARKANSAS 73.0 72.3 72.0URN-MISSISSIPPI 68.4 67.1 66.4 URN-TEXAS 71.1 71.3 71.6 URN-MISSOURI73.0 72.5 70.0 2014 Average 70.8 71.3 69.3 2015 URN-LOUISIANA 70.2 73.271.9 2014-2015 Grand Average 70.6 71.7 69.8

TABLE 13 Seedling vigor for CL272 (2012) YEAR TEST CL272 2012 CLPY-RRS 4

TABLE 14 Seedling vigor for CL272, CL261 and CL271 across several trialsat multiple locations in Louisiana (2013-2014). YEAR TEST CL272 CL261CL271 2013 CL MULTI-RRS 5 4 4 2014 CL MULTI-RRS 4 3 3 CLMULTI-EVANGELINE 3 3 3 CL MULTI-LAKE ARTHUR 4 4 5 2014 Average 4 3 42013-2014 Grand Average 4 4 4

TABLE 15 Seedling vigor for CL272, CL261, CL271 and Jupiter acrossseveral trials at multiple locations in Louisiana (2013-2015). YEAR TESTCL272 CL261 CL271 JUPITER 2013 CA-RRS 5 4 6 5 CA-ACADIA 4 4 5 5 2013Average 5 4 6 5 2014 CA-RRS 3 3 4 4 CA-ACADIA 4 4 4 5 CA-EVANGELINE 3 44 5 CA-JEFF DAVIS 6 5 6 8 CA-LAKE ARTHUR 6 5 5 7 2014 Average 4 4 5 62015 CA-RRS 3 3 3 5 CA-ACADIA 3 3 3 5 CA-EVANGELINE 4 4 5 4 CA-JEFFDAVIS 3 3 3 5 CA-LAKE ARTHUR 4 4 5 5 2015 Average 3 3 4 5 2013-2015Grand Average 4 4 4 5

TABLE 16 Seedling vigor for CL272, CL271 and Jupiter across severaltrials at multiple locations (2014-2015). YEAR TEST CL272 CL271 JUPITER2014 URN-LOUISIANA 5 3 5 URN-ARKANSAS 3 3 4 2014 Average 4 3 5 2015URN-LOUISIANA 4 4 5 URN-ARKANSAS 5 5 5 DATE OF PLANTING 3-RRS 3 3 5 DATEOF PLANTING 5-RRS 4 3 6 2015 Average 4 4 5 2014-2015 Grand Average 4 3 5

TABLE 17 Mean plant height (in) for CL272 (2012) YEAR TEST CL272 2012CLPY-RRS 38

TABLE 18 Mean plant height (in) for CL272, CL261 and CL271 acrossseveral trials at multiple locations in Louisiana (2013-2014). YEAR TESTCL272 CL261 CL271 2013 CL MULTI-RRS 38 39 37 CL MULTI-EVANGELINE 40 3939 CL MULTI-LAKE ARTHUR 39 40 39 CL MULTI-RICHLAND 38 39 40 2013 Average39 39 39 2014 CL MULTI-RRS 40 42 39 CL MULTI-EVANGELINE 42 41 38 CLMULTI-LAKE ARTHUR 38 39 37 2014 Average 40 41 38 2013-2014 Grand Average39 40 39

TABLE 19 Mean plant height (in) for CL272, CL261, CL271 and Jupiteracross several trials at multiple locations in Louisiana (2013-2015).YEAR TEST CL272 CL261 CL271 JUPITER 2013 CA-RRS 39 39 37 36 CA-ACADIA 3537 37 31 CA-EVANGELINE 38 37 38 34 CA-JEFF DAVIS 33 31 33 32 CA-ST.LANDRY 35 35 35 38 CA-FRANKLIN 45 47 46 42 2013 Average 37 38 38 35 2014CA-RRS 40 41 40 38 CA-ACADIA 42 41 41 41 CA-EVANGELINE 41 39 39 39CA-LAKE ARTHUR 38 39 37 39 CA-ST LANDRY 39 37 39 39 2014 Average 40 4039 39 2015 CA-RRS 39 38 36 39 CA-ACADIA 33 33 35 33 CA-EVANGELINE 31 3531 31 CA-JEFF DAVIS 38 37 37 37 CA-LAKE ARTHUR 37 37 37 36 CA-ST LANDRY39 39 38 36 2015 Average 36 37 36 35 2013-2015 Grand Average 38 38 37 37

TABLE 20 Mean plant height (in) for CL272, CL271 and Jupiter acrossseveral trials at multiple locations (2014-2015). YEAR TEST CL272 CL271JUPITER 2014 URN-LOUISIANA 39 38 38 URN-ARKANSAS 40 39 40URN-MISSISSIPPI 39 39 37 URN-MISSOURI 39 36 37 2014 Average 39 38 382015 URN-LOUISIANA 37 38 37 URN-ARKANSAS 40 42 37 URN-MISSISSIPPI 38 4039 DATE OF PLANTING 3-RRS 37 36 35 DATE OF PLANTING 5-RRS 31 30 32 2015Average 36 37 36 2014-2015 Grand Average 38 37 37

TABLE 21 Mean number of days to 50% heading for CL272 (2012) YEAR TESTCL272 2012 CLPY-RRS 88

TABLE 22 Mean number of days to 50% heading for CL272, CL261 and CL 271across several trials at multiple locations in Louisiana (2013-2014).YEAR TEST CL272 CL261 CL271 2013 CL MULTI-RRS 92 89 90 CLMULTI-EVANGELINE 92 86 88 CL MULTI-LAKE ARTHUR 103 95 100 CLMULTI-RICHLAND 70 70 74 2013 Average 89 85 88 2014 CL MULTI-RRS 86 83 85CL MULTI-EVANGELINE 90 87 90 CL MULTI-LAKE ARTHUR 90 88 89 2014 Average89 86 88 2013-2014 Grand Average 89 85 88

TABLE 23 Mean number of days to 50% heading for CL272, CL261, CL271 andJupiter across several trials at multiple locations in Louisiana(2013-2015). YEAR TEST CL272 CL261 CL271 JUPITER 2013 CA-RRS 93 88 91 92CA-ACADIA 93 90 92 97 CA-EVANGELINE 90 85 90 92 CA-JEFF DAVIS 87 81 8588 CA-ST. LANDRY 100 94 100 101 CA-FRANKLIN 73 68 73 73 2013 Average 8984 89 91 2014 CA-RRS 85 82 85 86 CA-ACADIA 86 85 88 90 CA-EVANGELINE 9087 90 92 CA-JEFF DAVIS 91 88 91 94 CA-LAKE ARTHUR 89 89 90 92 CA-STLANDRY 99 95 98 99 2014 Average 90 88 90 92 2015 CA-RRS 85 85 87 88CA-ACADIA 79 77 81 82 CA-EVANGELINE 72 70 74 73 CA-JEFF DAVIS 80 78 8280 CA-LAKE ARTHUR 83 82 84 81 2015 Average 80 78 82 81 2013-2015 GrandAverage 87 84 87 88

TABLE 24 Mean number of days to 50% heading for CL272, CL271 and Jupiteracross several trials at multiple locations (2014-2015). YEAR TEST CL272CL271 JUPITER 2014 URN-LOUISIANA 86 84 87 URN-ARKANSAS 87 86 84URN-MISSISSIPPI 82 83 81 URN-MISSOURI 96 97 95 2014 Average 88 88 872015 URN-LOUISIANA 86 86 88 URN-ARKANSAS 95 98 97 URN-MISSISSIPPI 85 8683 DATE OF PLANTING 3-RRS 75 74 75 DATE OF PLANTING 5-RRS 71 72 73 2015Average 82 83 83 2014-2015 Grand Average 85 85 85

TABLE 25 Reaction of CL272, CL261, CL271 and Jupiter to sheath blight(Rhizoctonia solani) (2014-2015). YEAR TEST CL272 CL261 CL271 JUPITER2014 CA-ACADIA 6.7 6.3 5.7 5.3 2015 CA-JEFF DAVIS 5.7 6.3 4.0 3.7CA-LAKE ARTHUR 2.3 3.3 2.3 1.3 2015 Average 4.0 4.8 3.2 2.5 2014-2015Grand Average 4.9 5.3 4.0 3.4 * Using a scale of 0 = very resistant to 9= very susceptible.

TABLE 26 Reaction of CL272, CL261, CL271 and Jupiter to blast(Pyricularia oryzae) (2014). YEAR TEST CL272 CL261 CL271 JUPITER 2014CA-EVANGELINE 2.0 1.7 2.3 1.3 CA-JEFF DAVIS 3.3 7.0 1.7 4.0 CA-LAKEARTHUR 3.3 4.7 2.0 2.3 2015 Average 2.9 4.5 2.0 2.5 * Using a scale of 0= very resistant to 9 = very susceptible.

TABLE 27 Reaction of 1202065, CL261, Caffey and Jupiter to narrow brownleaf spot (Cercospora oryzae) (2013). YEAR TEST CL272 CL261 CL271JUPITER 2015 CA-JEFF DAVIS 0.7 0.7 1.0 1.0 * Using a scale of 0 = veryresistant to 9 = very susceptible.

TABLE 28 Reaction of CL272, CL261, CL271 and Jupiter to bacterialpanicle blight (Burkhholderia glumae (2014-2015). YEAR TEST CL272 CL261CL271 JUPITER 2014 CA-ACADIA 4.7 5.0 3.3 2.3 2015 CA-EVANGELINE 3.0 3.04.3 2.3 2014-2015 Grand Average 3.9 4.0 3.8 2.3 * Using a scale of 0 =very resistant to 9 = very susceptible.

TABLE 29 Reaction of CL272, CL261, CL271 and Jupiter to thephysiological disorder straighthead (2014-2015). YEAR TEST CL272 CL261CL271 JUPITER 2014 RRS 5.3 5.5 4.5 4.5 2015 RRS 5.8 5.0 5.3 6.02014-2015 Grand Average 5.6 5.3 4.9 5.3

TABLE 30 2014 Crowley Disease Nursery YEAR DISEASE CL272 CL261 CL271JUPITER 2014 SHEATH BLIGHT 4.5 5.2 5.4 4.8 BLAST 2.2 5.6 0.0 1.6BACTERIAL 2.5 6.6 2.4 2.0 PANICLE BLIGHT

TABLE 31 2015 Crowley Disease Nursery YEAR DISEASE CL272 CL271 JUPITER2015 SHEATH BLIGHT 6.2 5.8 5.6 BLAST 5.0 3.2 2.0 NARROW BROWN 0.2 1.00.8 LEAF SPOT BACTERIAL 2.8 2.4 1.2 PANICLE BLIGHT

TABLE 32 Rough, brown and milled grain dimensions and weight of CL272,CL261, CL271 and Jupiter grown in Crowley, LA. Length Width L/W VarietyType mm mm Ratio Thickness Weight CL272 Rough 8.13 3.10 2.62 2.11 23.30Brown 6.09 2.67 2.28 1.87 19.87 Milled 5.63 2.52 2.23 1.83 17.02 CL261Rough 8.08 2.93 2.76 1.99 24.62 Brown 6.05 2.59 2.34 1.77 20.13 Milled5.75 2.51 2.29 1.70 16.91 CL271 Rough 8.38 3.13 2.68 2.33 26.67 Brown6.26 2.68 2.34 1.92 22.20 Milled 6.06 2.65 2.29 1.87 20.00 JUPITER Rough8.32 3.15 2.64 2.20 25.32 Brown 6.07 2.66 2.28 1.97 22.67 Milled 5.752.64 2.18 1.89 20.30

TABLE 33 Quality rating for CL272 (2015) YEAR LINE AMYLOSE ALKALI RATINGGEL TEMP 2015 CL272 16.4 6.2 LOW CL271 15.0 6.2 LOW JUPITER 14.7 6.0 LOW

TABLE 34 2015 RRS foundation field yields LINE YIELD B/A ACRES CL27254.0 17.7 CL111 46.4 11.0 CL151 50.3 10.1 CHENIERE 44.8 7.4 JUPITER 44.56.1 Foundation/Registered Seed 1,500 cwt

The variety is resistant to imidazolinone herbicides. The herbicideresistance profile is essentially the same as that of ‘CL161’ by directdescent. The herbicide tolerance allows ‘CL272,’ its hybrids, andderived varieties to be used with Clearfield™ rice technology andherbicides, including among others imazethapyr and imazamox, for theselective control of weeds, including red rice. See generally U.S. Pat.No. 6,943,280.

Herbicide Tolerance and Susceptibility Characteristics:

The variety is tolerant to some herbicides, and susceptible to someherbicides, that normally inhibit the growth of rice plants. Amongothers, the herbicide tolerance and susceptibility characteristics of‘CL272’ include or are expected to include the following. Thesecharacteristics are in some cases based on actual observations to date,and in other cases reflect assumptions based on direct descent from‘CL161’:

‘CL272’ expresses a mutant acetohydroxyacid synthase whose enzymaticactivity is directly resistant to normally-inhibitory levels of aherbicidally-effective imidazolinone;‘CL272’ is resistant to each of the following imidazolinone herbicides,at levels of the imidazolinone herbicides that would normally inhibitthe growth of a rice plant: imazethapyr, imazapic, imazaquin, imazamox,and imazapyr;‘CL272’ is resistant to each of the following sulfonylurea herbicides,at levels of the sulfonylurea herbicides that would normally inhibit thegrowth of a rice plant: nicosulfuron, metsulfuron methyl, thifensulfuronmethyl, and tribenuron methyl;‘CL272’ is sensitive to each of the following sulfonylurea herbicides,at levels of the sulfonylurea herbicides that would normally inhibit thegrowth of a rice plant: sulfometuron methyl, chlorimuron ethyl, andrimsulfuron.

This invention is also directed to methods for producing a rice plant bycrossing a first parent rice plant with a second parent rice plant,wherein the first or second rice plant is a rice plant from the line‘CL272.’ Further, both first and second parent rice plants may be fromthe cultivar ‘CL272,’ although it is preferred that one of the parentsshould be different. Methods that use the cultivar ‘CL272’ are also partof this invention, including crossing, selfing, backcrossing, hybridbreeding, crossing to populations, the other breeding methods discussedin this specification, and other breeding methods known to those ofskill in the art. Any plants produced using cultivar ‘CL272’ as a parentor ancestor are within the scope of this invention. The other parents orother lines used in such breeding programs may be any of the wide numberof rice varieties, cultivars, populations, experimental lines, and othersources of rice germplasm known in the art.

For example, this invention includes methods for producing afirst-generation hybrid rice plant by crossing a first parent rice plantwith a second parent rice plant, wherein either the first or secondparent rice plant is ‘CL272.’ Further, this invention is also directedto methods for producing a hybrid rice line derived from ‘CL272’ bycrossing ‘CL272’ with a second rice plant, and growing the progeny seed.The crossing and growing steps may be repeated any number of times.Breeding methods using the rice line ‘CL272’ are considered part of thisinvention, not only backcrossing and hybrid production, but alsoselfing, crosses to populations, and other breeding methods known in theart.

Optionally, either of the parents in such a cross, ‘CL272’ or the otherparent, may be produced in male-sterile form, using techniques known inthe art.

In one embodiment, a rice plant produced using cultivar ‘CL272’ as aparent or ancestor exhibits tolerance to applications of one or moreclasses of herbicides. Classes of herbicides include, but are notlimited to, acetohydroxyacid synthase (AHAS) inhibitors; bleachingherbicides such as hydroxyphenylpyruvate dioxygenase (HPPD) inhibitorsor phytoene desaturase (PDS) inhibitors; enolpyruvyl shikimate3-phosphate synthase (EPSPS) inhibitors such as glyphosate; glutaminesynthetase (GS) inhibitors such as glufosinate; auxinic herbicides,e.g., dicamba; lipid biosynthesis inhibitors such as ACCase inhibitors;or oxynil (i.e. bromoxynil or ioxynil) herbicides; protoporphyrinogen-IXoxidase (PPO) inhibitors other than saflufenacil (“other PPOinhibitors”) (e.g., acifluorfen, butafenacil, carfentrazone,flufenpyr-ethyl, fomesafen, flumiclorac, flumioxazin, lactofen,oxadiargyl, oxadiazon, oxyfluorfen, sulfentrazone); lipid biosynthesisinhibitors such as acetyl CoA carboxylase (ACCase) inhibitors; oxynil(i.e. bromoxynil or ioxynil) herbicides; ACCase-inhibitor(s);saflufenacil(s); p-hydroxyphenylpyruvate dioxygenase (4-HPPD)inhibitors; amide(s), e.g., propanil; and the like. AHAS-inhibitorherbicides include, e.g., imidazolinone herbicides, one or moresulfonylurea (SU) herbicides selected from the group consisting ofamidosulfuron, flupyrsulfuron, foramsulfuron, imazosulfuron,iodosulfuron, mesosulfuron, nicosulfuron, thifensulfuron, andtribenuron, agronomically acceptable salts and esters thereof, andcombinations thereof. ACCase inhibitor herbicides include, e.g., “dims”(e.g., cycloxydim, sethoxydim, clethodim, or tepraloxydim), “fops”(e.g., clodinafop, diclofop, fluazifop, haloxyfop, or quizalofop), and“dens” (such as pinoxaden).

For example, in some embodiments rice plants that are produced usingcultivar ‘CL272’ as a parent or ancestor may be tolerant to ACCaseinhibitors, such as “dims” (e.g., cycloxydim, sethoxydim, clethodim, ortepraloxydim), “fops” (e.g., clodinafop, diclofop, fluazifop, haloxyfop,or quizalofop), and “dens” (such as pinoxaden); to auxinic herbicides,such as dicamba; to EPSPS inhibitors, such as glyphosate; to other PPOinhibitors; and to GS inhibitors, such as glufosinate.

In addition to these classes of inhibitors, rice plants that areproduced using cultivar ‘CL272’ as a parent or ancestor may also betolerant to herbicides having other modes of action, for example,chlorophyll/carotenoid pigment inhibitors, cell membrane disruptors,photosynthesis inhibitors, cell division inhibitors, root inhibitors,shoot inhibitors, and combinations thereof.

Such tolerance traits may be expressed, e.g., as mutant acetohydroxyacidsynthase large subunit (AHASL) proteins, mutant ACCase proteins, mutantEPSPS proteins, or mutant glutamine synthetase proteins; or as a mutantnative, inbred, or transgenic aryloxyalkanoate dioxygenase (AAD or DHT),haloarylnitrilase (BXN), 2,2-dichloropropionic acid dehalogenase (DEH),glyphosate-N-acetyltransferase (GAT), glyphosate decarboxylase (GDC),glyphosate oxidoreductase (GOX), glutathione-S-transferase (GST),phosphinothricin acetyltransferase (PAT or bar), or cytochrome P450(CYP450) protein having herbicide-degrading activity.

The rice plants hereof can also be “stacked” with other traitsincluding, but not limited to, pesticidal traits such as Bt Cry andother proteins having pesticidal activity toward coleopteran,lepidopteran, nematode, or other pests; nutritional or nutraceuticaltraits such as modified oil content or oil profile traits, high proteinor high amino acid concentration traits, and other trait types known inthe art.

Furthermore, in another embodiment, rice plants are generated, e.g. bythe use of recombinant DNA techniques, breeding, or otherwise byselection for desired traits, that are able to synthesize one or moreproteins to improve their productivity, oil content, tolerance todrought, salinity or other growth-limiting environmental factors, ortolerance to arthropod pests, and fungal, bacterial, or viral pathogensof rice plants.

Furthermore, in other embodiments, rice plants are generated, e.g. bythe use of recombinant DNA techniques, breeding, or otherwise byselection for desired traits to contain a modified amount of one or moresubstances or to contain one or more new substances, for example, toimprove human or animal nutrition, e.g. health-promoting long-chainomega-3 fatty acids or unsaturated omega-9 fatty acids. (Cf. Nexera®canola, Dow Agro Sciences, Canada).

Furthermore, in some embodiments, rice plants are generated, e.g. by theuse of recombinant DNA techniques, breeding, or otherwise by selectionfor desired traits to contain increased amounts of vitamins, minerals,or improved profiles of nutraceutical compounds.

In one embodiment, rice plants are produced using cultivar ‘CL272’ as aparent or ancestor so that the new rice plants, relative to a wild-typerice plant, comprise an increased amount of, or an improved profile of,a compound selected from the group consisting of: glucosinolates (e.g.,glucoraphanin (4-methylsulfinylbutyl-glucosinolate), sulforaphane,3-indolylmethyl-glucosinolate (glucobrassicin), or1-methoxy-3-indolylmethyl-glucosinolate (neoglucobrassicin)); phenolics(e.g., flavonoids (e.g., quercetin, kaempferol), hydroxycinnamoylderivatives (e.g., 1,2,2′-trisinapoylgentiobiose,1,2-diferuloylgentiobiose, 1,2′-disinapoyl-2-feruloylgentiobiose, or3-O-caffeoyl-quinic (neochlorogenic acid)); and vitamins and minerals(e.g., vitamin C, vitamin E, carotene, folic acid, niacin, riboflavin,thiamine, calcium, iron, magnesium, potassium, selenium, and zinc).

In another embodiment, rice plants are produced using cultivar ‘CL272’as a parent or ancestor so that the new rice plants, relative to awild-type rice plant, comprise an increased amount of, or an improvedprofile of, a compound selected from the group consisting of:progoitrin; isothiocyanates; indoles (products of glucosinolatehydrolysis); glutathione; carotenoids such as beta-carotene, lycopene,and the xanthophyll carotenoids such as lutein and zeaxanthin; phenolicscomprising the flavonoids such as the flavonols (e.g. quercetin, rutin),the flavins/tannins (such as the procyanidins comprising coumarin,proanthocyanidins, catechins, and anthocyanins); flavones;phytoestrogens such as coumestans; lignans; resveratrol; isoflavonese.g. genistein, daidzein, and glycitein; resorcyclic acid lactones;organosulfur compounds; phytosterols; terpenoids such as carnosol,rosmarinic acid, glycyrrhizin and saponins; chlorophyll; chlorphyllin,sugars, anthocyanins, and vanilla.

Herbicides

Herbicidal compositions that may be used in conjunction with theinvention include herbicidally active ingredients (A.I.), and theiragronomically acceptable salts and esters.

The herbicidal compositions can be applied in any agronomicallyacceptable format. For example, they can be formulated as ready-to-sprayaqueous solutions, powders, or suspensions; as concentrated or highlyconcentrated aqueous, oily or other solutions, suspensions ordispersions; as emulsions, oil dispersions, pastes, dusts, granules, orother broadcastable formats. The herbicidal compositions can be appliedby any method known in the art, including, for example, spraying,atomizing, dusting, spreading, watering, seed treatment, or co-plantingin admixture with the seed. The formulations depend on the intendedpurpose; in any case, they should ensure a fine distribution of theA.I.s. A herbicidal composition can be selected according to thetolerances of a particular plant, and the plant can be selected fromamong those having stacked tolerance traits.

In some embodiments, where the A.I. includes an AHAS inhibitor, the AHASinhibitor may be selected from: (1) the imidazolinones, e.g. imazamox,imazethapyr, imazapyr, imazapic, imazaquin, and imazamethabenz;preferably imazamox, imazethapyr, imazapyr, or imazapic; (2) thesulfonylureas, e.g. amidosulfuron, azimsulfuron, bensulfuron,cinosulfuron, ethoxysulfuron, flupyrsulfuron, foramsulfuron,imazosulfuron, iodosulfuron, mesosulfuron, metsulfuron, nicosulfuron,thifensulfuron, and tribenuron; (3) the pyrimidinyloxy[thio]benzoates,e.g. including the pyrimidinyloxybenzoates (e.g., bispyribac,pyriminobac, and pyribenzoxim) and the pyrimidinylthiobenzoates (e.g.,pyrithiobac and pyriftalid); and (4) the sulfonamides, e.g. includingthe sulfonylaminocarbonyltriazolinones (e.g., flucarbazone andpropoxycarbazone) and the triazolopyrimidines (e.g., cloransulam,diclosulam, florasulam, flumetsulam, metosulam, and penoxsulam). Theagronomically acceptable salts and esters of the foregoing are alsoincluded, as are combinations thereof.

Optional A.I.s of other types include, but are not limited toagronomically-acceptable fungicides such as strobilurins, e.g.,pyraclostrobin, alone or in combination with, e.g., boscalid,epiconazole, metaconazole, tebuconazole, kresoxim-methyl, and the like;insecticides such as nematicides, lepidoptericides, coleoptericides;molluscicides), and others known in the art (e.g., malathion,pyrethrins/pyrethrum, carbaryl, spinosad, permethrin, bifenthrin, andesfenvalerate).

Examples of herbicides that are ACCase inhibitors include, but are notlimited to, cyclohexanedione herbicides (DIMs, also referred to as:cyclohexene oxime cyclohexanedione oxime; and CHD), aryloxyphenoxypropionate herbicides (also referred to as aryloxyphenoxy propanoate;aryloxyphenoxyalkanoate; oxyphenoxy; APP; AOPP; APA; APPA; FOP), andphenylpyrazole herbicides (also known as DENs; and sometimes referred tounder the more general class of phenylpyrazoles such as pinoxaden (e.g.,herbicides sold under the trade names Axial and Traxos)). In somemethods of controlling weeds or growing herbicide-tolerant plants, atleast one herbicide is selected from the group consisting of sethoxydim,cycloxydim, tepraloxydim, haloxyfop, haloxyfop-P or a derivative of oneof these herbicides. Table C lists examples of herbicides that interferewith ACCase activity.

TABLE C Examples of ACCase inhibitors. Examples of Synonyms ACCaseInhibitor Class Company and Trade Names alloxydim DIM BASF Fervin,Kusagard, NP-48Na, BAS 9021H, Carbodimedon, Zizalon butroxydim DIMSyngenta Falcon, ICI-A0500, Butroxydim clethodim DIM Valent Select,Prism, Centurion, RE-45601, Motsa Clodinafop- FOP Syngenta Discover,Topik, CGA 184 927 propargyl clofop FOP Fenofibric Acid, Alopexcloproxydim FOP chlorazifop FOP cycloxydim DIM BASF Focus, Laser,Stratos, BAS 517H cyhalofop-butyl FOP Dow Clincher, XDE 537, DEH 112,Barnstorm diclofop-methyl FOP Bayer Hoegrass, Hoelon, Illoxan, HOE23408, Dichlorfop, Illoxan fenoxaprop-P-ethyl FOP Bayer Super Whip,Option Super, Exel Super, HOE-46360, Aclaim, Puma S, Fusion fenthiapropFOP Taifun; Joker fluazifop-P-butyl FOP Syngenta Fusilade, Fusilade2000, Fusilade DX, ICI-A 0009, ICI-A 0005, SL-236, IH-773B, TF-1169,Fusion haloxyfop-etotyl FOP Dow Gallant, DOWCO 453EE haloxyfop-methylFOP Dow Verdict, DOWCO 453ME haloxyfop-P-methyl FOP Dow Edge, DE 535isoxapyrifop FOP Metamifop FOP Dongbu NA pinoxaden DEN Syngenta Axialprofoxydim DIM BASF Aura, Tetris, BAS 625H, Clefoxydim propaquizafop FOPSyngenta Agil, Shogun, Ro 17-3664, Correct quizalofop-P-ethyl FOP DuPontAssure, Assure II, DPX-Y6202-3, Targa Super, NC-302, Quizafopquizalofop-P-tefuryl FOP Uniroyal Pantera, UBI C4874 sethoxydim DIM BASFPoast, Poast Plus, NABU, Fervinal, NP-55, Sertin, BAS 562H, Cyethoxydim,Rezult tepraloxydim DIM BASF BAS 620H, Aramo, Caloxydim tralkoxydim DIMSyngenta Achieve, Splendor, ICI-A0604, Tralkoxydime, Tralkoxidym trifopFOP

Examples of herbicides that are auxinic herbicides include, but are notlimited to, those shown in Table D.

TABLE D Examples of Auxinic herbicides. Classification of AuxinicHerbicides (HRAC Group ‘O’; WSSA Group ‘4’) Subgroup Member CompoundPhenoxy- Clomeprop carboxylic- cloprop (“3-CPA”) acid Subgroup4-chlorophenoxyacetic acid (“4-CPA”) 2-(4-chlorophenoxy)propionic acid(“4-CPP”) 2,4-dichlorophenoxy acetic acid (“2,4-D”)(3,4-dichlorophenoxy)acetic acid (“3,4-DA”)4-(2,4-dichlorophenoxy)butyric acid (“2,4-DB”)2-(3,4-dichlorophenoxy)propionic acid (“3,4-DP”)tris[2-(2,4-dichlorophenoxy)ethyl]phosphite (“2,4-DEP”) dichlorprop(“2,4-DP”) 2,4,5-trichlorophenoxyacetic acid (“2,4,5-T”) fenoprop(“2,4,5-TP”) 2-(4-chloro-2-methylphenoxy)acetic acid (“MCPA”)4-(4-chloro-2-methylphenoxy)butyric acid (“MCPB”) mecoprop (“MCPP”)Benzoic acid Chloramben Subgroup Dicamba Tricamba 2,3,6-trichlorobenzoicacid (“TBA”) Pyridine Aminopyralid carboxylic Clopyralid acid SubgroupFluroxypyr Picloram Triclopyr Quinoline Quinclorac carboxylic Quinmeracacid Subgroup Other Benazolin Subgroup

In one embodiment, a saflufenacil A.I. is, e.g.:2-chloro-5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-4-fluoro-N-[[methyl(1-methylethyl) amino]sulfonyl]benzamide (CAS:N′-{2-chloro-4-fluoro-5-[1,2,3,6-tetrahydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)pyrimidin-1-yl]benzoyl}-N-isopropyl-N-methylsulfamide; Reg. No.: 372137-35-4);BAS-H800). As used herein a named compound, (e.g., “saflufenacil”)includes the compound (e.g., saflufenacil) as well as its salts andesters, unless expressly stated otherwise.

The herbicidal compositions can also comprise auxiliary ingredients thatare customary for the formulation of crop protection agents.

Examples of auxiliaries customary for the formulation of crop protectionagents include inert auxiliaries, solid carriers, surfactants (such asdispersants, protective colloids, emulsifiers, wetting agents, andtackifiers), organic and inorganic thickeners, penetrants (such aspenetration-enhancing organosilicone surfactants or acidic sulfatechelates, e.g., CT-301™ available from Cheltec, Inc.), safeners,bactericides, antifreeze agents, antifoams, colorants, and adhesives.Formulations of the herbicide compositions useful herein can be preparedaccording to any method known to be useful for that purpose in the art.

Examples of thickeners (i.e. compounds that impart modified flowproperties, i.e. high viscosity in the state of rest and low viscosityin motion) are polysaccharides, such as xanthan gum (Kelzan® fromKelco), Rhodopol® 23 (Rhone Poulenc) or Veegum® (from R.T. Vanderbilt),and also organic and inorganic sheet minerals, such as Attaclay® (fromEngelhard).

Examples of antifoams are silicone emulsions (for example, Silikon® SRE,Wacker or Rhodorsil® from Rhodia), long-chain alcohols, fatty acids,salts of fatty acids, organofluorine compounds, and mixtures thereof.

Bactericides can optionally be added for stabilizing the aqueousherbicidal formulations. Examples of bactericides are bactericides basedon diclorophen and benzyl alcohol hemiformal (Proxel® from ICI orActicide® RS from Thor Chemie and Kathon® MK from Rohm & Haas), and alsoisothiazolinone derivatives, such as alkylisothiazolinones andbenzisothiazolinones (Acticide MBS from Thor Chemie).

Examples of antifreeze agents are ethylene glycol, propylene glycol,urea, and glycerol.

Examples of colorants include members of colorant classes such as thesparingly water-soluble pigments and the water-soluble dyes. Someexamples include the dyes known under the names Rhodamin B, C.I. PigmentRed 112, C.I. Solvent Red 1, pigment blue 15:4, pigment blue 15:3,pigment blue 15:2, pigment blue 15:1, pigment blue 80, pigment yellow 1,pigment yellow 13, pigment red 112, pigment red 48:2, pigment red 48:1,pigment red 57:1, pigment red 53:1, pigment orange 43, pigment orange34, pigment orange 5, pigment green 36, pigment green 7, pigment white6, pigment brown 25, basic violet 10, basic violet 49, acid red 51, acidred 52, acid red 14, acid blue 9, acid yellow 23, basic red 10, andbasic red 108.

Examples of adhesives are polyvinylpyrrolidone, polyvinyl acetate,polyvinyl alcohol and tylose.

Suitable inert auxiliaries are, for example, the following: mineral oilfractions of medium to high boiling point, such as kerosene and dieseloil; coal tar oils; oils of vegetable or animal origin; aliphatic,cyclic and aromatic hydrocarbons, for example paraffins,tetrahydronaphthalene, alkylated naphthalenes and their derivatives,alkylated benzenes and their derivatives, alcohols such as methanol,ethanol, propanol, butanol and cyclohexanol, ketones such ascyclohexanone or strongly polar solvents, for example amines such asN-methylpyrrolidone, and water.

Suitable carriers include liquid and solid carriers.

Liquid carriers include e.g. non-aqueous solvents such as cyclic andaromatic hydrocarbons, e.g. paraffins, tetrahydronaphthalene, alkylatednaphthalenes and their derivatives, alkylated benzenes and theirderivatives, alcohols such as methanol, ethanol, propanol, butanol andcyclohexanol, ketones such as cyclohexanone, strongly polar solvents,e.g. amines such as N-methylpyrrolidone, and water, as well as mixturesthereof.

Solid carriers include e.g. mineral earths such as silicas, silica gels,silicates, talc, kaolin, limestone, lime, chalk, bole, loess, clay,dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate andmagnesium oxide, ground synthetic materials, fertilizers such asammonium sulfate, ammonium phosphate, ammonium nitrate and ureas, andproducts of vegetable origin, such as cereal meal, tree bark meal, woodmeal, nutshell meal, cellulose powders, and other solid carriers.

Suitable surfactants (e.g., adjuvants, wetting agents, tackifiers,dispersants, or emulsifiers) include the alkali metal salts, alkalineearth metal salts and ammonium salts of aromatic sulfonic acids, forexample lignosulfonic acids (e.g. Borrespers-types, Borregaard),phenolsulfonic acids, naphthalenesulfonic acids (Morwet types, AkzoNobel) and dibutylnaphthalenesulfonic acid (Nekal types, BASF AG), andof fatty acids, alkyl- and alkylarylsulfonates, alkyl sulfates, laurylether sulfates and fatty alcohol sulfates, and salts of sulfated hexa-,hepta- and octadecanols, and also of fatty alcohol glycol ethers,condensates of sulfonated naphthalene and its derivatives withformaldehyde, condensates of naphthalene or of the naphthalenesulfonicacids with phenol and formaldehyde, polyoxyethylene octylphenol ether,ethoxylated isooctyl-, octyl- or nonylphenol, alkylphenyl ortributylphenyl polyglycol ether, alkylaryl polyether alcohols,isotridecyl alcohol, fatty alcohol/ethylene oxide condensates,ethoxylated castor oil, polyoxyethylene alkyl ethers or polyoxypropylenealkyl ethers, lauryl alcohol polyglycol ether acetate, sorbitol esters,lignosulfite waste liquors and proteins, denatured proteins,polysaccharides (e.g. methylcellulose), hydrophobically modifiedstarches, polyvinyl alcohol (Mowiol types, Clariant), polycarboxylates(BASF AG, Sokalan types), polyalkoxylates, polyvinylamine (BASF AG,Lupamine types), polyethyleneimine (BASF AG, Lupasol types),polyvinylpyrrolidone and copolymers thereof.

Powders, materials for broadcasting and dusts can be prepared by mixingor concomitant grinding of the A.I.s together with a solid carrier.

Granules, for example coated granules, impregnated granules andhomogeneous granules, can be prepared by binding the A.I.s to solidcarriers.

Aqueous use forms can be prepared from emulsion concentrates,suspensions, pastes, wettable powders or water-dispersible granules byadding water.

To prepare emulsions, pastes or oil dispersions, the herbicidalcompositions can be homogenized in water by means of a wetting agent,tackifier, dispersant or emulsifier. Alternatively, it is also possibleto prepare concentrates comprising active compound, wetting agent,tackifier, dispersant or emulsifier and, if desired, solvent or oil,preferably suitable for dilution or dispersion with water.

The concentration of the herbicide(s) present in the herbicidalcomposition can be varied within wide ranges. In general, theformulations comprise approximately from 0.001% to 98% by weight,preferably 0.01 to 95% by weight of at least one active ingredient. Insome embodiments, the A.I.s are employed in a purity of from 90% to100%, preferably 95% to 100% (measured, e.g., according to NMR or IRspectra).

In some formulations, the herbicides are suspended, emulsified, ordissolved. The formulations may be in the form of aqueous solutions,powders, suspensions, or highly-concentrated aqueous, oily or othersuspensions or dispersions, aqueous emulsions, aqueous microemulsions,aqueous suspo-emulsions, oil dispersions, pastes, dusts, materials forspreading, or granules.

The herbicides or the herbicidal compositions comprising them can beapplied pre-emergence, post-emergence or pre-planting, or together withthe seed. It is also possible to apply the herbicidal composition oractive compounds by planting seed pretreated with the herbicidalcompositions or active compounds.

In a further embodiment, the herbicides or herbicidal compositions canbe applied by treating seed. The treatment of seeds comprisesessentially any of the procedures familiar to the person skilled in theart (e.g., seed dressing, seed coating, seed dusting, seed soaking, seedfilm coating, seed multilayer coating, seed encrusting, seed drippingand seed pelleting). The herbicidal compositions can be applied dilutedor undiluted.

It may furthermore be beneficial to apply the herbicides alone or incombination with other herbicides, or in the form of a mixture withother crop protection agents, for example together with agents forcontrolling pests or phytopathogenic fungi or bacteria. Also of interestis the miscibility with mineral salt solutions, which are employed fortreating nutritional and trace element deficiencies. Other additivessuch as non-phytotoxic oils and oil concentrates can also be added.

Moreover, it may be useful to apply the herbicides in combination withsafeners. Safeners are compounds that prevent or reduceherbicide-induced injury to useful plants without having a major impacton the herbicidal action of the herbicides. They can be applied eitherbefore sowing (e.g. on seed treatments, shoots or seedlings) or in thepre-emergence application or post-emergence application of the cropplant. The safeners and the herbicides can be applied simultaneously orin succession.

Safeners include e.g. (quinolin-8-oxy)acetic acids,1-phenyl-5-haloalkyl-1H-1,2,4-triazol-3-carboxylic acids,1-phenyl-4,5-dihydro-5-alkyl-1H-pyrazol-3,5-dicarboxylic acids,4,5-dihydro-5,5-diaryl-3-isoxazol carboxylic acids, dichloroacetamides,alpha-oximinophenylacetonitriles, acetophenonoximes,4,6-dihalo-2-phenylpyrimidines,N-[[4-(aminocarbonyl)phenyl]sulfonyl]-2-benzoic amides, 1,8-naphthalicanhydride, 2-halo-4-(haloalkyl)-5-thiazol carboxylic acids, benoxacor,cloquintocet, cyometrinil, cyprosulfamide, dichlormid, dicyclonon,dietholate, fenchlorazole, fenclorim, flurazole, fluxofenim, furilazole,isoxadifen, mefenpyr, mephenate, naphthalic anhydride, oxabetrinil,4-(dichloroacetyl)-1-oxa-4-azaspiro[4.5]decane (MON4660, CAS 71526-07-3)and 2,2,5-trimethyl-3-(dichloroacetyl)-1,3-oxazolidine (R-29148, CAS52836-31-4), phosphorthiolates and N-alkyl-O-phenyl-carbamates and theiragriculturally acceptable salts and their agriculturally acceptablederivatives such amides, esters, and thioesters.

Those skilled in the art will recognize that some compounds used asherbicides, safeners, etc. are capable of forming geometric isomers, forexample E/Z isomers, enantiomers, diastereomers, or other stereoisomers.In general, it is possible to use either pure isomers or mixtures ofisomers. For example, some of the aryloxyphenoxy propionate herbicidesare chiral, and some of them are commonly used in enantiomericallyenriched or enantiopure form, e.g. clodinafop, cyhalofop, fenoxaprop-P,fluazifop-P, haloxyfop-P, metamifop, propaquizafop or quizalofop-P. As afurther example, glufosinate may be used in enantiomerically enriched orenantiopure form, also known as glufosinate-P. Alternatively, thecompounds may be used in racemic mixtures or other mixtures of geometricisomers.

Controlling Weeds

Rice plants of the invention can be used in conjunction withherbicide(s) to which they are tolerant. Herbicides can be applied tothe rice plants of the invention using any techniques known to thoseskilled in the art. Herbicides can be applied at any point in the riceplant cultivation process. For example, herbicides can be appliedpre-planting, at planting, pre-emergence, post-emergence or combinationsthereof. Herbicides may be applied to seeds and dried to form a layer onthe seeds.

In some embodiments, seeds are treated with a safener, followed by apost-emergence application of herbicide(s). In one embodiment, thepost-emergence application of herbicide(s) occurs about 7 to 10 daysfollowing planting of safener-treated seeds. In some embodiments, thesafener is cloquintocet, dichlormid, fluxofenim, or combinationsthereof.

In other aspects, the present invention provides a method forcontrolling weeds at a locus for growth of a rice plant or plant partthereof, the method comprising applying a composition comprisingherbicide(s) to the locus.

In some aspects, the present invention provides a method for controllingweeds at a locus for growth of a plant, the method comprising applying aherbicide composition to the locus; wherein said locus is: (a) a locusthat contains a rice plant or seed capable of producing a rice plant; or(b) a locus that will contain the rice plant or the seed after applyingthe herbicide composition.

The following are non-limiting examples describing different riceculturing methods including the application of herbicide(s).

In the post-flood, post-emergence (transplanted) method, rice is grownto about the 2-4 leaf stage away from the field. The field is floodedand tilled (puddled) until a blend of mud is achieved. The rice plantsare then transplanted into the mud. Herbicide application typicallytakes place before or after flooding.

In the post-flood, post-emergence (water-seeded) method, rice is soakedfor about 24 hours or more, and then is sown into the surface of ashallow flooded field. Herbicide application is typically made afterweed germination.

In the pre-flood, post-emergence, direct-seeded (broadcast or drilled)method, rice is broadcast or planted with a planter under the soilsurface. The field may be flushed (watered) to promote rice growth. Thefield is flooded about a week or more after the planting as the plantsgerminate. Herbicide application takes place typically before the flood,but after emergence of the rice plants.

In the pre-flood, post-emergence (Southeast Asia style) method, rice issoaked for about 24 hours or more. The field is puddled to the rightconsistency and drained. The pre-germinated seeds are then broadcast tothe surface of the soil. Flooding takes place as the rice develops.Herbicide application normally takes place before the flooding, butafter the emergence of the rice plants.

In the pre-emergence or delayed pre-emergence method, seeds are planted,usually with a planter. Herbicide is applied before emergence of therice or weeds.

Herbicide compositions can be applied, e.g., as foliar treatments, soiltreatments, seed treatments, or soil drenches. Application can be made,e.g., by spraying, dusting, broadcasting, or any other mode known in theart.

In one embodiment, herbicides can be used to control the growth of weedsthat may be found growing in the vicinity of the rice plants of theinvention. In embodiments of this type, a herbicide to which the riceplant of the invention is tolerant can be applied to the plot at aconcentration sufficient to kill or inhibit the growth of weeds.Concentrations of herbicide sufficient to kill or inhibit the growth ofweeds are known in the art.

In another embodiment, the present invention provides a method forcontrolling weeds in the vicinity of rice plants. The method comprisesapplying an effective amount of herbicide(s) to the weeds and to therice plant, wherein the rice plant has increased tolerance to theherbicide(s) when compared to a wild-type rice plant.

In another aspect, herbicide(s) can be used as a seed treatment. In someembodiments, an effective concentration or an effective amount ofherbicide(s), or a composition comprising an effective concentration oran effective amount of herbicide(s) can be applied directly to the seedsprior to or during the sowing of the seeds. Seed treatment formulationsmay additionally comprise binders, and optionally colorants as well.

Binders can be added to improve the adhesion of the active materialsonto the seeds after treatment. Suitable binders include, e.g., blockcopolymers, EO/PO surfactants, polyvinylalcohols, polyvinylpyrrolidones,polyacrylates, polymethacrylates, polybutenes, polyisobutylenes,polystyrene, polyethyleneamines, polyethyleneamides, polyethyleneimines(e.g., Lupasol®, Polymin®), polyethers, polyurethanes, polyvinylacetate,tylose, and copolymers derived from these polymers.

The term “seed treatment” includes all suitable seed treatmenttechniques known in the art, such as seed dressing, seed coating, seeddusting, seed soaking, and seed pelleting. Soil may be treated byapplying a formulation containing the herbicide (e.g., a granularformulation), for example with a seed drill, with optionally one or moresolid or liquid, agriculturally acceptable carriers, and optionally withone or more agriculturally acceptable surfactants.

The present invention also comprises seeds coated with or containing aseed treatment formulation comprising herbicide(s).

The term “coated with or containing” generally signifies that the activeingredient is for the most part on the surface of the seed at the timeof application, although a greater or lesser part of the ingredient maypenetrate into the seed, depending on the method of application. Whenthe seed is planted, it may absorb the active ingredient.

In some embodiments, the seed treatment with herbicide(s) or with aformulation comprising the herbicide(s) is applied by spraying ordusting the seeds, or otherwise treating the seeds, before the seeds aresown.

In other aspects, the present invention provides a method for combatingundesired vegetation or controlling weeds, comprising contacting seedsof the rice plants with herbicide(s) before sowing, or afterpre-germination, or both. The method can further comprise sowing theseeds, for example, in soil in a field or in a potting medium in agreenhouse. The method finds particular use in combating undesiredvegetation or controlling weeds in the immediate vicinity of the seed.The control of undesired vegetation is understood as the killing ofweeds, or otherwise retarding or inhibiting the normal growth of weeds.Weeds, in the broadest sense, are understood as meaning all those plantsthat grow in locations where they are undesired.

The weeds that may be treated include, for example, dicotyledonous andmonocotyledonous weeds. Monocotyledonous weeds include, but are notlimited to, weeds of the genera: Echinochloa, Setaria, Panicum,Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus,Avena, Oryza, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria,Fimbristyslis, Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum,Sphenoclea, Dactyloctenium, Agrostis, Alopecurus, and Apera.Dicotyledonous weeds include, but are not limited to, weeds of thegenera: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis,Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus, Portulaca,Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium,Carduus, Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica,Abutilon, Emex, Datura, Viola, Galeopsis, Papaver, Centaurea, Trifolium,Ranunculus, and Taraxacum.

Examples of red/weedy rice include, but are not limited to, Oryzalongistaminata, Oryza sativa L. var. sylvatica, Oryza latifolia, Oryzabarthii A. Chev, Oryza punctata, and Oryza rufipogon.

Examples of Echinochloa spp. include, but are not limited to,Echinochloa colona, Echinochloa crusgalli, and Echinochloa oryzicola.

In addition, the weeds treated with the present invention can include,for example, crop plants that are growing in an undesired location.

In still further aspects, loci, plants, plant parts, or seeds aretreated with an agronomically acceptable composition that does notcontain an A.I. For example, the treatment may comprise one or moreagronomically-acceptable carriers, diluents, excipients, plant growthregulators, and the like; or an adjuvant, such as a surfactant, aspreader, a sticker, a penetrant, a drift-control agent, a crop oil, anemulsifier, a compatibility agent, or combinations thereof.

In other aspects, the present invention provides a product prepared fromthe rice plants of the invention, for example, brown rice (e.g., cargorice), broken rice (e.g., chits, brewer's rice), polished rice (e.g.,milled rice), rice hulls (e.g., husks, chaff), rice bran, rice pollards,rice mill feed, rice flour, rice oil, oiled rice bran, de-oiled ricebran, arrak, rice wine, poultry litter, and animal feed.

Further Embodiments of the Invention

As used herein, the term “plant” includes plant cells, plantprotoplasts, plant cells of tissue culture from which rice plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants or parts of plants, such as pollen, flowers, embryos, ovules,seeds, pods, leaves, stems, roots, anthers and the like. Thus, anotheraspect of this invention is to provide for cells that, upon growth anddifferentiation, produce a cultivar having essentially all of thephysiological and morphological characteristics of ‘CL272.’

Techniques for transforming with and expressing desired structural genesand cultured cells are known in the art. Also, as known in the art, ricemay be transformed and regenerated such that whole plants containing andexpressing desired genes under regulatory control are obtained. Generaldescriptions of plant expression vectors and reporter genes andtransformation protocols can be found, for example, in Gruber et al.,“Vectors for Plant Transformation, in Methods in Plant Molecular Biology& Biotechnology” in Glich et al. (Eds. pp. 89-119, CRC Press, 1993). Forexample, expression vectors and gene cassettes with the GUS reporter areavailable from Clone Tech Laboratories, Inc. (Palo Alto, Calif.), andexpression vectors and gene cassettes with luciferase reporter areavailable from Promega Corp. (Madison, Wis.). General methods ofculturing plant tissues are provided, for example, by Maki et al.,“Procedures for Introducing Foreign DNA into Plants” in Methods in PlantMolecular Biology & Biotechnology, Glich et al., (Eds. pp. 67-88 CRCPress, 1993); by Phillips et al., “Cell-Tissue Culture and In-VitroManipulation” in Corn & Corn Improvement, 3rd Edition; and by Sprague etal., (Eds. pp. 345-387) American Society of Agronomy Inc., 1988. Methodsof introducing expression vectors into plant tissue include the directinfection or co-cultivation of plant cells with Agrobacteriumtumefaciens, Horsch et al., Science, 227:1229 (1985). Descriptions ofAgrobacterium vectors systems and methods for Agrobacterium-mediatedgene transfer are provided by Gruber et al., supra.

Useful methods include but are not limited to expression vectorsintroduced into plant tissues using a direct gene transfer method suchas microprojectile-mediated delivery, DNA injection, electroporation andthe like. More preferably expression vectors are introduced into planttissues using the microprojectile media delivery with biolistic device-or Agrobacterium-mediated transformation. Transformed plants obtainedwith the germplasm of ‘CL272’ are intended to be within the scope ofthis invention.

The present invention also provides rice plants regenerated from atissue culture of the ‘CL272’ variety or hybrid plant. As is known inthe art, tissue culture can be used for the in vitro regeneration of arice plant. For example, see Chu, Q. R. et al. (1999) “Use of bridgingparents with high anther culturability to improve plant regeneration andbreeding value in rice,” Rice Biotechnology Quarterly, 38:25-26; Chu, Q.R. et al., “A novel plant regeneration medium for rice anther culture ofSouthern U.S. crosses,” Rice Biotechnology Quarterly, 35:15-16 (1998);Chu, Q. R. et al., “A novel basal medium for embryogenic callusinduction of Southern US crosses,” Rice Biotechnology Quarterly,32:19-20 (1997); and Oono, K., “Broadening the Genetic Variability ByTissue Culture Methods,” Jap. J. Breed., 33 (Supp. 2), 306-307 (1983).Thus, another aspect of this invention is to provide cells that, upongrowth and differentiation, produce rice plants having all, oressentially all, of the physiological and morphological characteristicsof variety ‘CL272.’

Unless context clearly indicates otherwise, references in thespecification and claims to ‘CL272’ should be understood also to includesingle gene conversions of ‘CL272’ with a gene encoding a trait such as,for example, male sterility, other sources of herbicide resistance,resistance for bacterial, fungal, or viral disease, insect resistance,male fertility, enhanced nutritional quality, industrial usage, yieldstability and yield enhancement.

Duncan et al., Planta, 165:322-332 (1985) reflects that 97% of theplants cultured that produced callus were capable of plant regeneration.Subsequent experiments with both inbreds and hybrids produced 91%regenerable callus that produced plants. In a further study, Songstad etal., Plant Cell Reports, 7:262-265 (1988) reported several mediaadditions that enhanced regenerability of callus of two inbred lines.Other published reports also indicate that “nontraditional” tissues arecapable of producing somatic embryogenesis and plant regeneration. K. P.Rao et al., Maize Genetics Cooperation Newsletter, 60:64-65 (1986),refers to somatic embryogenesis from glume callus cultures and B. V.Conger et al., Plant Cell Reports, 6:345-347 (1987) reported somaticembryogenesis from the tissue cultures of corn leaf segments. Thesemethods of obtaining plants are routinely used with a high rate ofsuccess.

Tissue culture of corn (maize) is described in European PatentApplication No. 160,390. Corn tissue culture procedures, which may beadapted for use with rice, are also described in Green et al., “PlantRegeneration in Tissue Culture of Maize,” Maize for Biological Research(Plant Molecular Biology Association, Charlottesville, Va., pp. 367-372,1982) and in Duncan et al., “The Production of Callus Capable of PlantRegeneration from Immature Embryos of Numerous Zea Mays Genotypes,” 165Planta, 322:332 (1985). Thus, another aspect of this invention is toprovide cells that, upon growth and differentiation, produce rice plantshaving all, or essentially all, of the physiological and morphologicalcharacteristics of hybrid rice line ‘CL272.’ See T. P. Croughan et al.,(Springer-Verlag, Berlin, 1991) Rice (Oryza sativa. L): Establishment ofCallus Culture and the regeneration of Plants, in Biotechnology inAgriculture and Forestry (19-37).

With the advent of molecular biological techniques that allow theisolation and characterization of genes that encode specific proteinproducts, it is now possible to routinely engineer plant genomes toincorporate and express foreign genes, or additional or modifiedversions of native, or endogenous, genes (perhaps driven by differentpromoters) in order to alter the traits of a plant in a specific manner.Such foreign, additional, and modified genes are herein referred tocollectively as “transgenes.” In recent years, several methods forproducing transgenic plants have been developed, and the presentinvention, in particular embodiments, also relates to transformedversions of ‘CL272.’

An expression vector is constructed that will function in plant cells.Such a vector comprises a DNA coding sequence that is under the controlof or is operatively linked to a regulatory element (e.g., a promoter).The expression vector may contain one or more such operably linkedcoding sequence/regulatory element combinations. The vector(s) may be inthe form of a plasmid or virus, and can be used alone or in combinationwith other plasmids or viruses to provide transformed rice plants.

Expression Vectors

Expression vectors commonly include at least one genetic “marker,”operably linked to a regulatory element (e.g., a promoter) that allowstransformed cells containing the marker to be either recovered bynegative selection, i.e., inhibiting growth of cells that do not containthe selectable marker gene, or by positive selection, i.e., screeningfor the product encoded by the genetic marker. Many commonly usedselectable marker genes for plant transformation are known in the art,and include, for example, genes that code for enzymes that metabolicallydetoxify a selective chemical inhibitor such as an antibiotic or aherbicide, or genes that encode an altered target that is insensitive tosuch an inhibitor. Positive selection methods are also known in the art.

For example, a commonly used selectable marker gene for planttransformation is that for neomycin phosphotransferase II (nptII),isolated from transposon Tn5, whose expression confers resistance tokanamycin. See Fraley et al., Proc. Natl. Acad. Sci. U.S.A., 80:4803(1983). Another commonly used selectable marker gene is the hygromycinphosphotransferase gene, which confers resistance to the antibiotichygromycin. See Vanden Elzen et al., Plant Mol. Biol., 5:299 (1985).

Additional selectable marker genes of bacterial origin that conferresistance to one or more antibiotics include gentamycin acetyltransferase, streptomycin phosphotransferase, aminoglycoside-3′-adenyltransferase, and the bleomycin resistance determinant. Hayford et al.,Plant Physiol., 86:1216 (1988), Jones et al., Mol. Gen. Genet., 210:86(1987), Svab et al., Plant Mol. Biol., 14:197 (1990); Plant Mol. Biol.,7:171 (1986). Other selectable marker genes confer resistance toherbicides such as glyphosate, glufosinate, or broxynil. Comai et al.,Nature, 317:741-744 (1985); Gordon-Kamm et al., Plant Cell, 2:603-618(1990); and Stalker et al., Science, 242:419-423 (1988).

Selectable marker genes for plant transformation of non-bacterial origininclude, for example, mouse dihydrofolate reductase, plant5-enolpyruvylshikimate-3-phosphate synthase, and plant acetolactatesynthase. Eichholtz et al., Somatic Cell Mol. Genet. 13:67 (1987); Shahet al., Science, 233:478 (1986); and Charest et al., Plant Cell Rep.,8:643 (1990).

Another class of marker genes for plant transformation employs screeningof presumptively transformed plant cells, rather than selection forresistance to a toxic substance such as an antibiotic. These markergenes are particularly useful to quantify or visualize the spatialpattern of expression of a gene in specific tissues, and are frequentlyreferred to as reporter genes because they may be fused to the targetgene or regulatory sequence. Commonly used reporter genes includeglucuronidase (GUS), galactosidase, luciferase, chloramphenicol, andacetyltransferase. See Jefferson, R. A., Plant Mol. Biol. Rep., 5:387(1987); Teeri et al., EMBO J., 8:343 (1989); Koncz et al., Proc. Natl.Acad. Sci. U.S.A., 84:131 (1987); and DeBlock et al., EMBO J., 3:1681(1984). Another approach to identifying relatively rare transformationevents has been the use of a gene that encodes a dominant constitutiveregulator of the Zea mays anthocyanin pigmentation pathway. Ludwig etal., Science, 247:449 (1990).

The Green Fluorescent Protein (GFP) gene has been used as a marker forgene expression in prokaryotic and eukaryotic cells. See Chalfie et al.,Science, 263:802 (1994). GFP and mutants of GFP may be used asscreenable markers.

Genes included in expression vectors are driven by a nucleotide sequencecomprising a regulatory element, for example, a promoter. Many suitablepromoters are known in the art, as are other regulatory elements thatmay be used either alone or in combination with promoters.

As used herein, “promoter” refers to a region of DNA upstream ordownstream from the transcription initiation site, a region that isinvolved in recognition and binding of RNA polymerase and other proteinsto initiate transcription. A “plant promoter” is a promoter capable ofinitiating transcription in plant cells. Examples of promoters underdevelopmental control include promoters that preferentially initiatetranscription in certain tissues, such as leaves, roots, seeds, fibers,xylem vessels, tracheids, or sclerenchyma. Such promoters are referredto as “tissue-preferred.” Promoters that initiate transcription only incertain tissue are referred to as “tissue-specific.” A “cell type”specific promoter primarily drives expression in certain cell types inone or more organs, for example, vascular cells in roots or leaves. An“inducible” promoter is a promoter that is under environmental control.Examples of environmental conditions that may induce transcription byinducible promoters include anaerobic conditions or the presence oflight. Tissue-specific, tissue-preferred, cell type specific, andinducible promoters are examples of “non-constitutive” promoters. A“constitutive” promoter is a promoter that is generally active undermost environmental conditions.

A. Inducible Promoters

An inducible promoter is operably linked to a gene for expression inrice. Optionally, the inducible promoter is operably linked to anucleotide sequence encoding a signal sequence that is operably linkedto a gene for expression in rice. With an inducible promoter the rate oftranscription increases in response to an inducing agent.

Any suitable inducible promoter may be used in the present invention.See Ward et al., Plant Mol. Biol., 22:361-366 (1993). Examples includethose from the ACEI system, which responds to copper, Meft et al., PNAS,90:4567-4571 (1993); In2 gene from maize, which responds tobenzenesulfonamide herbicide safeners, Hershey et al., Mol. GenGenetics, 227:229-237 (1991); Gatz et al., Mol. Gen. Genetics, 243:32-38(1994); and Tet repressor from Tn10, Gatz, Mol. Gen. Genetics,227:229-237 (1991). A preferred inducible promoter is one that respondsto an inducing agent to which plants do not normally respond, forexample, the inducible promoter from a steroid hormone gene, thetranscriptional activity of which is induced by a glucocorticosteroidhormone. See Schena et al., Proc. Natl. Acad. Sci., U.S.A. 88:0421(1991).

B. Constitutive Promoters

A constitutive promoter is operably linked to a gene for expression inrice, or the constitutive promoter is operably linked to a nucleotidesequence encoding a signal sequence that is operably linked to a genefor expression in rice.

Constitutive promoters may also be used in the instant invention.Examples include promoters from plant viruses such as the 35S promoterfrom cauliflower mosaic virus, Odell et al., Nature, 313:810-812 (1985),and the promoters from the rice actin gene, McElroy et al., Plant Cell,2:163-171 (1990); ubiquitin, Christensen et al., Plant Mol. Biol.,12:619-632 (1989) and Christensen et al., Plant Mol. Biol. 18:675-689(1992); pEMU, Last et al., Theor. Appl. Genet., 81:581-588 (1991); MAS,Velten et al., EMBO J., 3:2723-2730 (1984); and maize H3 histone,Lepetit et al., Mol. Gen. Genetics, 231:276-285 (1992) and Atanassova etal., Plant Journal, 2 (3): 291-300 (1992).

An ALS (AHAS) promoter, such as the Xba1/Nco1 fragment 5′ from theBrassica napus ALS3 structural gene (or a nucleotide sequence homologousto or otherwise similar to said Xba1/Nco1 fragment), may be used as aconstitutive promoter. See PCT Application WO 96/30530. The promoterfrom a rice ALS (AHAS) gene may also be used. See the sequencesdisclosed in PCT Application WO 01/85970; and U.S. Pat. No. 6,943,280.

C. Tissue-Specific or Tissue-Preferred Promoters

A tissue-specific promoter is operably linked to a gene for expressionin rice. Optionally, the tissue-specific promoter is operably linked toa nucleotide sequence encoding a signal sequence that is operably linkedto a gene for expression in rice. Transformed plants produce theexpression product of the transgene exclusively, or preferentially, inspecific tissue(s).

Any tissue-specific or tissue-preferred promoter may be used in theinstant invention. Examples of tissue-specific or tissue-preferredpromoters include those from the phaseolin gene, Murai et al., Science,23:476-482 (1983), and Sengupta-Gopalan et al., Proc. Natl. Acad. Sci.U.S.A., 82:3320-3324 (1985); a leaf-specific and light-induced promotersuch as that from cab or rubisco, Simpson et al., EMBO J.,4(11):2723-2729 (1985) and Timko et al., Nature, 318:579-582 (1985); ananther-specific promoter such as that from LAT52, Twell et al., Mol.Gen. Genetics, 217:240-245 (1989); a pollen-specific promoter such asthat from Zm13, Guerrero et al., Mol. Gen. Genetics, 244:161-168 (1993);or a microspore-preferred promoter such as that from apg, Twell et al.,Sex. Plant Reprod., 6:217-224 (1993).

Signal Sequences for Targeting Proteins to Subcellular Compartments

Transport of protein or peptide molecules produced by transgenes to asubcellular compartment such as a chloroplast, vacuole, peroxisome,glyoxysome, cell wall, or mitochondrion, or for secretion into anapoplast, is accomplished by operably linking a nucleotide sequenceencoding a signal sequence to the 5′ or 3′ end of a gene encoding theprotein or peptide of interest. Targeting sequences at the 5′ or 3′ endof the structural gene may determine, during protein synthesis andprocessing, where the encoded protein is ultimately compartmentalized.

Many signal sequences are known in the art. See, for example, Becker etal., Plant Mol. Biol., 20:49 (1992); Close, P. S., Master's Thesis, IowaState University (1993); Knox, C. et al., “Structure and Organization ofTwo Divergent Alpha-Amylase Genes from Barley,” Plant Mol. Biol., 9:3-17(1987); Lerner et al., Plant Physiol., 91:124-129 (1989); Fontes et al.,Plant Cell, 3:483-496 (1991); Matsuoka et al., Proc. Natl. Acad. Sci.,88:834 (1991); Gould et al., J. Cell. Biol., 108:1657 (1989); Creissenet al., Plant J., 2:129 (1991); Kalderon et al., “A short amino acidsequence able to specify nuclear location,” Cell, 39:499-509 (1984); andSteifel et al., “Expression of a maize cell wall hydroxyproline-richglycoprotein gene in early leaf and root vascular differentiation,”Plant Cell, 2:785-793 (1990).

Foreign Protein Genes and Agronomic Genes

Agronomically significant genes that may be transformed into rice plantsin accordance with the present invention include, for example, thefollowing:

1. Genes that Confer Resistance to Pests or Disease:

-   -   A. Plant disease resistance genes. Plant defenses are often        activated by specific interaction between the product of a        disease resistance gene (R) in the plant and the product of a        corresponding avirulence (Avr) gene in the pathogen. A plant may        be transformed with a cloned resistance gene to engineer plants        that are resistant to specific pathogen strains. See, e.g.,        Jones et al., Science 266:789 (1994) (cloning of the tomato Cf-9        gene for resistance to Cladosporium fulvum); Martin et al.,        Science 262:1432 (1993) (tomato Pto gene for resistance to        Pseudomonas syringae pv. Tomato encodes a protein kinase); and        Mindrinos et al., Cell 78:1089 (1994) (Arabidopsis RSP2 gene for        resistance to Pseudomonas syringae).    -   B. A Bacillus thuringiensis protein, a derivative thereof, or a        synthetic polypeptide modeled thereon. See, e.g., Geiser et al.,        Gene 48:109 (1986), disclosing the cloning and nucleotide        sequence of a Bt-endotoxin gene. DNA molecules encoding        endotoxin genes may be obtained from American Type Culture        Collection, Manassas, Va., e.g., under ATCC Accession Nos.        40098, 67136, 31995, and 31998.    -   C. A lectin. See, for example, Van Damme et al., Plant Molec.        Biol. 24:25 (1994), disclosing the nucleotide sequences of        several Clivia miniata mannose-binding lectin genes.    -   D. A vitamin-binding protein such as avidin. See PCT Application        US93/06487. This disclosure teaches the use of avidin and avidin        homologues as larvicides against insect pests.    -   E. An enzyme inhibitor, e.g., a protease or proteinase inhibitor        or an amylase inhibitor. See, e.g., Abe et al., J. Biol. Chem.        262:16793 (1987) (nucleotide sequence of rice cysteine        proteinase inhibitor); Huub et al., Plant Molec. Biol.        21:985 (1993) (nucleotide sequence of cDNA encoding tobacco        proteinase inhibitor 1); and Sumitani et al., Biosci. Biotech.        Biochem. 57:1243 (1993) (nucleotide sequence of Streptomyces        nitrosporeus-amylase inhibitor).    -   F. An insect-specific hormone or pheromone such as an        ecdysteroid and juvenile hormone, a variant thereof, a mimetic        based thereon, or an antagonist or agonist thereof. See, e.g.,        Hammock et al., Nature, 344:458 (1990), disclosing baculovirus        expression of cloned juvenile hormone esterase, an inactivator        of juvenile hormone.    -   G. An insect-specific peptide or neuropeptide that, upon        expression, disrupts the physiology of the affected pest. See,        e.g., Regan, J. Biol. Chem. 269:9 (1994) (expression cloning        yields DNA coding for insect diuretic hormone receptor); and        Pratt et al., Biochem. Biophys. Res. Comm., 163:1243 (1989) (an        allostatin in Diploptera puntata). See also U.S. Pat. No.        5,266,317 to Tomalski et al., disclosing genes encoding        insect-specific, paralytic neurotoxins.    -   H. An insect-specific venom produced in nature by a snake, a        wasp, etc. For example, see Pang et al., Gene, 116:165 (1992),        concerning heterologous expression in plants of a gene coding        for a scorpion insectotoxic peptide.    -   I. An enzyme responsible for hyperaccumulation of a monoterpene,        a sesquiterpene, a steroid, hydroxamic acid, a phenylpropanoid        derivative or another non-protein molecule with insecticidal        activity.    -   J. An enzyme involved in the modification, including        post-translational modification, of a biologically active        molecule; e.g., a glycolytic enzyme, a proteolytic enzyme, a        lipolytic enzyme, a nuclease, a cyclase, a transaminase, an        esterase, a hydrolase, a phosphatase, a kinase, a phosphorylase,        a polymerase, an elastase, a chitinase, or a glucanase, either        natural or synthetic. See PCT Application WO 9302197 to Scott et        al., which discloses the nucleotide sequence of a callase gene.        DNA molecules that contain chitinase-encoding sequences can be        obtained, for example, from the American Type Culture Collection        under Accession Nos. 39637 and 67152. See also Kramer et al.,        Insect Biochem. Molec. Biol. 23:691 (1993), which discloses the        nucleotide sequence of a cDNA encoding tobacco hookworm        chitinase; and Kawalleck et al., Plant Molec. Biol., 21:673        (1993), which discloses the nucleotide sequence of the parsley        ubi4-2 polyubiquitin gene.    -   K. A molecule that stimulates signal transduction. See, e.g.,        Botella et al., Plant Molec. Biol., 24:757 (1994), which        discloses nucleotide sequences for mung bean calmodulin cDNA        clones; and Griess et al., Plant Physiol., 104:1467 (1994),        which discloses the nucleotide sequence of a maize calmodulin        cDNA clone.    -   L. An antimicrobial or amphipathic peptide. See PCT Application        WO 9516776 (disclosing peptide derivatives of Tachyplesin that        inhibit fungal plant pathogens); and PCT Application WO 9518855        (disclosing synthetic antimicrobial peptides that confer disease        resistance).    -   M. A membrane permease, a channel former or a channel blocker.        See, e.g., Jaynes et al., Plant Sci., 89:43 (1993), which        discloses heterologous expression of a cecropin lytic peptide        analog to render transgenic tobacco plants resistant to        Pseudomonas solanacearum.    -   N. A viral-invasive protein or a complex toxin derived        therefrom. For example, the accumulation of viral coat proteins        in transformed plant cells induces resistance to viral infection        or disease development caused by the virus from which the coat        protein gene is derived, as well as by related viruses. Coat        protein-mediated resistance has been conferred upon transformed        plants against alfalfa mosaic virus, cucumber mosaic virus,        tobacco streak virus, potato virus X, potato virus Y, tobacco        etch virus, tobacco rattle virus, and tobacco mosaic virus. See        Beachy et al., Ann. Rev. Phytopathol., 28:451 (1990).    -   O. An insect-specific antibody or an immunotoxin derived        therefrom. Thus, an antibody targeted to a critical metabolic        function in the insect gut inactivates an affected enzyme,        killing the insect. See Taylor et al., Abstract #497, Seventh        Int'l Symposium on Molecular Plant-Microbe Interactions        (Edinburgh, Scotland, 1994) (enzymatic inactivation in        transgenic tobacco via production of single-chain antibody        fragments).    -   P. A virus-specific antibody. See, e.g., Tavladoraki et al.,        Nature, 366:469 (1993), showing protection of transgenic plants        expressing recombinant antibody genes from virus attack.    -   Q. A developmental-arrest protein produced in nature by a        pathogen or a parasite. For example, fungal        endo-1,4-D-polygalacturonases facilitate fungal colonization and        plant nutrient release by solubilizing plant cell wall        homo-1,4-D-galacturonase. See Lamb et al., Bio/Technology,        10:1436 (1992). The cloning and characterization of a gene that        encodes a bean endopolygalacturonase-inhibiting protein is        described by Toubart et al., Plant J., 2:367 (1992).    -   R. A developmental-arrest protein produced in nature by a plant.        For example, Logemann et al., Bio/Technology, 10:305 (1992)        reported that transgenic plants expressing the barley        ribosome-inactivating gene have an increased resistance to        fungal disease.        2. Genes that Confer Additional Resistance to a Herbicide,        Beyond that which is Inherent in ‘CL272,’ for Example:    -   A. A herbicide that inhibits the growing point or meristem, such        as an imidazolinone or a sulfonylurea. Exemplary genes in this        category code for mutant ALS and AHAS enzymes as described, for        example, by Lee et al., EMBO J., 7:1241 (1988); and Miki et al.,        Theor. Appl. Genet., 80:449 (1990), respectively. See,        additionally, U.S. Pat. Nos. 5,545,822; 5,736,629; 5,773,703;        5,773,704; 5,952,553; 6,274,796; 6,943,280; 7,019,196;        7,345,221; 7,399,905; 7,495,153; 7,754,947; and 7,786,360;        published International Patent Application WO 2010/059656;        (currently) unpublished International Patent Applications        PCT/US2010/051749, and PCT/US2010/051780; and published U.S.        patent applications US 2007/0061915, US 2010/0257623, and US        2009/0025108. Resistance to AHAS-acting herbicides may be        through a mechanism other than a resistant AHAS enzyme. See,        e.g., U.S. Pat. No. 5,545,822.    -   B. Glyphosate. Resistance may be imparted by mutant        5-enolpyruvl-3-phosphikimate synthase (EPSP) and aroA genes.        Other phosphono compounds such as glufosinate. Resistance may be        imparted by phosphinothricin acetyl transferase, PAT and        Streptomyces hygroscopicus phosphinothricin-acetyl transferase,        bar, genes. Pyridinoxy or phenoxy propionic acids and        cyclohexones. Resistance may be imparted by ACCase        inhibitor-encoding genes. See, e.g., U.S. Pat. No. 4,940,835 to        Shah et al., which discloses the nucleotide sequence of a form        of EPSP that confers glyphosate resistance. A DNA molecule        encoding a mutant aroA gene can be obtained under ATCC Accession        Number 39256, and the nucleotide sequence of the mutant gene is        disclosed in U.S. Pat. No. 4,769,061 to Comai. European Patent        Application No. 0333033 to Kumada et al.; and U.S. Pat. No.        4,975,374 to Goodman et al., disclose nucleotide sequences of        glutamine synthetase genes that confer resistance to herbicides        such as L-phosphinothricin. The nucleotide sequence of a        phosphinothricin-acetyl-transferase gene is provided in European        Application No. 0242246 to Leemans et al. and DeGreef et al.,        Bio/Technology, 7:61 (1989), describing the production of        transgenic plants that express chimeric bar genes coding for        phosphinothricin acetyl transferase activity. Examples of genes        conferring resistance to phenoxy propionic acids and        cyclohexones, such as sethoxydim and haloxyfop, are the Acc1-S1,        Acc1-S2, and Acc1-S3 genes described by Marshall et al., Theor.        Appl. Genet., 83:435 (1992).

C. A herbicide that inhibits photosynthesis, such as a triazine (psbAand gs+ genes) or a benzonitrile (nitrilase gene). Przibilla et al.,Plant Cell, 3:169 (1991), describe the transformation of Chlamydomonaswith plasmids encoding mutant psbA genes. Nucleotide sequences fornitrilase genes are disclosed in U.S. Pat. No. 4,810,648 to Stalker, andDNA molecules containing these genes are available under ATCC AccessionNos. 53435, 67441, and 67442. Cloning and expression of DNA coding for aglutathione S-transferase is described by Hayes et al., Biochem. J.,285:173 (1992).

3. Genes that Confer or Contribute to a Value-Added Trait, Such as:

-   -   A. Modified fatty acid metabolism, for example, by transforming        a plant with an antisense sequence to stearyl-ACP desaturase, to        increase stearic acid content of the plant. See Knultzon et al.,        Proc. Natl. Acad. Sci. U.S.A. 89:2624 (1992).    -   B. Decreased Phytate Content        -   1) Introduction of a phytase-encoding gene would enhance            breakdown of phytate, adding more free phosphate to the            transformed plant. See, e.g., Van Hartingsveldt et al.,            Gene, 127:87 (1993), which discloses the nucleotide sequence            of an Aspergillus niger phytase gene.        -   2) A gene may be introduced to reduce phytate content. For            example, this may be accomplished by cloning, and then            reintroducing DNA associated with an allele that is            responsible for maize mutants characterized by low levels of            phytic acid, or a homologous or analogous mutation in rice            may be used. See Raboy et al., Maydica, 35:383 (1990).    -   C. Carbohydrate composition may be modified, for example, by        transforming plants with a gene coding for an enzyme that alters        the branching pattern of starch. See Shiroza et al., J.        Bacteol., 170:810 (1988) (nucleotide sequence of Streptococcus        mutant fructosyltransferase gene); Steinmetz et al., Mol. Gen.        Genet., 20:220 (1985) (nucleotide sequence of Bacillus subtilis        levansucrase gene); Pen et al., Bio/Technology, 10:292 (1992)        (production of transgenic plants that express Bacillus        licheniformis amylase); Elliot et al., Plant Molec. Biol.,        21:515 (1993) (nucleotide sequences of tomato invertase genes);        Søgaard et al., J. Biol. Chem., 268:22480 (1993) (site-directed        mutagenesis of barley amylase gene); and Fisher et al., Plant        Physiol., 102:1045 (1993) (maize endosperm starch branching        enzyme 11).

Methods for Rice Transformation

Numerous methods for plant transformation are known in the art,including both biological and physical transformation protocols. See,e.g., Miki, et al., “Procedures for Introducing Foreign DNA into Plants”in Methods in Plant Molecular Biology and Biotechnology; Glick B. R. andThompson, J. E. (Eds.) (CRC Press, Inc., Boca Raton, 1993), pp. 67-88.In addition, expression vectors and in vitro culture methods for plantcell or tissue transformation and regeneration of plants are known inthe art. See, e.g., Gruber et al., “Vectors for Plant Transformation” inMethods in Plant Molecular Biology and Biotechnology, Glick B. R. andThompson, J. E. (Eds.) (CRC Press, Inc., Boca Raton, 1993), pp. 89-119.

A. Agrobacterium-Mediated Transformation

One method for introducing an expression vector into plants is based onthe natural transformation system of Agrobacterium. See, e.g., Horsch etal., Science, 227:1229 (1985). A. tumefaciens and A. rhizogenes areplant pathogenic soil bacteria that genetically transform plant cells.The Ti and Ri plasmids of A. tumefaciens and A. rhizogenes,respectively, carry genes responsible for genetic transformation ofplants. See, e.g., Kado, C. I., Crit. Rev. Plant Sci., 10:1 (1991).Descriptions of Agrobacterium vector systems and methods forAgrobacterium-mediated gene transfer are provided by Gruber et al.,supra; Miki et al., supra; and Moloney, et al., Plant Cell Reports,8:238 (1989). See also U.S. Pat. No. 5,591,616.

B. Direct Gene Transfer

Despite the fact the host range for Agrobacterium-mediatedtransformation is broad, it is more difficult to transform some cerealcrop species and gymnosperms via this mode of gene transfer, althoughsuccess has been achieved in both rice and corn. See Hiei et al., ThePlant Journal, 6:271-282 (1994); and U.S. Pat. No. 5,591,616. Othermethods of plant transformation exist as alternatives toAgrobacterium-mediated transformation.

A generally applicable method of plant transformation ismicroprojectile-mediated (so-called “gene gun”) transformation, in whichDNA is carried on the surface of microprojectiles, typically 1 to 4 μmin diameter. The expression vector is introduced into plant tissues witha biolistic device that accelerates the microprojectiles to typicalspeeds of 300 to 600 m/s, sufficient to penetrate plant cell walls andmembranes. Sanford et al., Part. Sci. Technol., 5:27 (1987); Sanford, J.C., Trends Biotech., 6:299 (1988); Klein et al., Bio/Technology,6:559-563 (1988); Sanford, J. C., Physiol Plant, 7:206 (1990); and Kleinet al., Biotechnology, 10:268 (1992). Various target tissues may bebombarded with DNA-coated microprojectiles to produce transgenic plants,including, for example, callus (Type I or Type II), immature embryos,and meristematic tissue.

Another method for physical delivery of DNA to plants is sonication oftarget cells. Zhang et al., Bio/Technology, 9:996 (1991). Alternatively,liposome or spheroplast fusion has been used to introduce expressionvectors into plants. Deshayes et al., EMBO J., 4:2731 (1985); andChristou et al., Proc Natl. Acad. Sci. U.S.A., 84:3962 (1987). Directuptake of DNA into protoplasts, using CaCl₂) precipitation, polyvinylalcohol or poly-L-ornithine, has also been reported. Hain et al., Mol.Gen. Genet., 199:161 (1985); and Draper et al., Plant Cell Physiol.,23:451 (1982). Electroporation of protoplasts and whole cells andtissues has also been described. Donn et al., in Abstracts of VIIthInternational Congress on Plant Cell and Tissue Culture IAPTC, A2-38, p.53 (1990); D'Halluin et al., Plant Cell, 4:1495-1505 (1992); and Spenceret al., Plant Mol. Biol., 24:51-61 (1994).

Following transformation of rice target tissues, expression of aselectable marker gene allows preferential selection of transformedcells, tissues, or plants, using regeneration and selection methodsknown in the art.

These methods of transformation may be used for producing a transgenicinbred line. The transgenic inbred line may then be crossed with anotherinbred line (itself either transformed or non-transformed), to produce anew transgenic inbred line. Alternatively, a genetic trait that has beenengineered into a particular rice line may be moved into another lineusing traditional crossing and backcrossing techniques. For example,backcrossing may be used to move an engineered trait from a public,non-elite inbred line into an elite inbred line, or from an inbred linecontaining a foreign gene in its genome into an inbred line or linesthat do not contain that gene.

The term “inbred rice plant” should be understood also to include singlegene conversions of an inbred line. Backcrossing methods can be usedwith the present invention to improve or introduce a characteristic intoan inbred line.

Many single gene traits have been identified that are not regularlyselected for in the development of a new inbred line, but that may beimproved by crossing and backcrossing. Single gene traits may or may notbe transgenic. Examples of such traits include male sterility, waxystarch, herbicide resistance, resistance for bacterial or fungal orviral disease, insect resistance, male fertility, enhanced nutritionalquality, yield stability, and yield enhancement. These genes aregenerally inherited through the nucleus. Known exceptions to the nucleargenes include some genes for male sterility that are inheritedcytoplasmically, but that still act functionally as single gene traits.Several single gene traits are described in U.S. Pat. Nos. 5,777,196;5,948,957; and 5,969,212.

Deposit Information

A sample of seeds of the rice cultivar designated ‘CL272’ was depositedwith the American Type Culture Collection (ATCC), 10801 UniversityBoulevard, Manassas, Va. 20110-2209 on 19 May 2016, and was assignedATCC Accession No. PTA-123124. This deposit was made under the BudapestTreaty.

MISCELLANEOUS

The complete disclosures of all references cited in this specificationare hereby incorporated by reference. Also incorporated by reference isthe complete disclosure of priority application 62/344,657. In the eventof an otherwise irreconcilable conflict, however, the presentspecification shall control.

What is claimed:
 1. A rice plant of the variety ‘CL272,’ arepresentative sample of seeds of said variety having been depositedunder ATCC Accession No. PTA-123124; or an F₁ hybrid of the variety‘CL272.’
 2. The rice plant of claim 1, wherein said rice plant is a riceplant of the variety ‘CL272.’
 3. A rice seed of the rice plant of claim2, or a rice seed capable of producing said rice plant.
 4. The riceplant of claim 1, wherein said rice plant is an F₁ hybrid of the variety‘CL272.’
 5. A rice seed capable of producing the rice plant of claim 4.6. A rice seed of the rice plant of claim 1, or a rice seed capable ofproducing said rice plant.
 7. The seed of claim 6, wherein said seed istreated with an AHAS-inhibiting herbicide.
 8. The seed of claim 7,wherein the AHAS-inhibiting herbicide comprises a herbicidally effectiveimidazolinone.
 9. The seed of claim 7, wherein the AHAS-inhibitingherbicide comprises a herbicidally effective sulfonylurea.
 10. Pollen ofthe plant of claim
 1. 11. An ovule of the plant of claim
 1. 12. Acomposition comprising a product prepared from the rice plant ofclaim
 1. 13. A tissue culture of regenerable cells or protoplastsproduced from the rice plant of claim
 1. 14. The tissue culture of claim13, wherein said cells or protoplasts are produced from a tissueselected from the group consisting of embryos, meristematic cells,pollen, leaves, anthers, roots, root tips, flowers, seeds, and stems.15. A method for producing rice plants, said method comprising plantinga plurality of rice seeds of the rice plant of claim 1, or a pluralityof rice seeds capable of producing said rice plant, under conditionsfavorable for the growth of rice plants.
 16. The method of claim 15,additionally comprising the step of applying herbicide in the vicinityof the rice plants to control weeds, wherein the herbicide normallyinhibits acetohydroxyacid synthase, at levels of the herbicide thatwould normally inhibit the growth of a rice plant.
 17. The method ofclaim 16, wherein the herbicide comprises a sulfonylurea.
 18. The methodof claim 16, wherein the herbicide comprises an imidazolinone.
 19. Themethod of claim 16, wherein the herbicide comprises imazethapyr orimazamox.
 20. A method of producing an insect resistant rice plant, saidmethod comprising transforming the rice plant of claim 1 with atransgene that confers insect resistance.
 21. An insect resistant riceplant or rice seed produced by the method of claim
 20. 22. A method ofproducing a disease resistant rice plant, said method comprisingtransforming the rice plant of claim 1 with a transgene that confersdisease resistance.
 23. A disease resistant rice plant or rice seedproduced by the method of claim
 22. 24. A method of producing a riceplant with modified fatty acid or modified carbohydrate metabolism, saidmethod comprising transforming the rice plant of claim 1 with at leastone transgene encoding a protein selected from the group consisting offructosyltransferase, levansucrase, alpha-amylase, invertase, andstarch-branching enzyme; or encoding an antisense sequence tostearyl-ACP desaturase.
 25. A rice plant or rice seed having modifiedfatty acid or modified carbohydrate metabolism, wherein said rice plantor rice seed is produced by the method of claim
 24. 26. A method ofintroducing a desired trait into rice cultivar ‘CL272,’ said methodcomprising the steps of: (a) crossing plants as recited in claim 1 withplants of another rice line expressing the desired trait, to produceprogeny plants; (b) selecting progeny plants that express the desiredtrait, to produce selected progeny plants.
 27. A rice seed from aprogeny plant produced by the method of claim 26; wherein, if said riceseed is grown, then the rice plants grown from said rice seed willexpress the imidazolinone herbicide resistance characteristics of‘CL272.’
 28. The method of claim 26, additionally comprising the step ofplanting a plurality of rice seed produced by selected higher generationbackcross progeny plants under conditions favorable for the growth ofrice plants.
 29. The method of claim 28, additionally comprising thestep of applying herbicide in the vicinity of the rice plants to controlweeds, wherein the herbicide normally inhibits acetohydroxyacidsynthase, at levels of the herbicide that would normally inhibit thegrowth of a rice plant.
 30. The method of claim 29, wherein theherbicide comprises a sulfonylurea.
 31. The method of claim 29, whereinthe herbicide comprises an imidazolinone.
 32. The method of claim 29,wherein the herbicide comprises imazethapyr or imazamox.
 33. The methodof claim 26, wherein the selected progeny plants are hybrid plants. 34.A method of introducing a desired trait into rice cultivar ‘CL272,’ saidmethod comprising the steps of: (a) crossing plants as recited in claim1 with plants of another rice line expressing the desired trait, toproduce progeny plants; (b) selecting progeny plants that express thedesired trait, to produce selected progeny plants; (c) crossing theselected progeny plants with plants as recited in claim 2 to produce newprogeny plants; (d) selecting new progeny plants that express both thedesired trait and some or all of the physiological and morphologicalcharacteristics of rice cultivar ‘CL272,’ to produce new selectedprogeny plants; and (e) repeating steps (c) and (d) three or more timesin succession, to produce selected higher generation backcross progenyplants that express both the desired trait and essentially all of thephysiological and morphological characteristics of rice cultivar‘CL272,’ as described in the VARIETY DESCRIPTION INFORMATION of thespecification, determined at a 5% significance level, when grown in thesame environmental conditions; and wherein the selected plants expressthe imidazolinone herbicide resistance characteristics of ‘CL272.’